It's three months since Maddy vanished and her parents are grieving in very different ways. He's thinking about moving back to Britain and starting to rebuild their lives. She's still lost in despair and cannot bear to leave Portugal

On Wednesday evening, Gerry McCann flew back to Portugal after a hectic three day trip to Washington DC - the latest and farthest-flung staging post on his mission to champion the cause of abducted children and maximise publicity for his missing daughter, Madeleine.

Settling into his sleeper bed in Virgin Upper Class (mindful of the sniping about the £946,000 fund for Madeleine, of which £67,000 has been spent, he bought an economy ticket, but was given a complimentary upgrade), the 39-year-old heart consultant was exhausted.

Fighting on: Gerry McCann has taken the search for his daughter all the way to the Whitehouse

But onlookers remarked that he appeared buoyant for the first time in the three months since his four-year-old daughter was taken.

Ultimately, of course, the McCanns will measure success and failure solely on whether Madeleine is returned safely.

However, according to Justine McGuinness, a Liberal Democrat parliamentary candidate who was recently appointed the Find Madeleine campaign manager, Mr McCann felt the venture had gone "extremely well".

This is despite the fact Mr McCann had encountered some unexpectedly hostile questions, notably from Chris Cuomo, the Good Morning America breakfast show anchor.

"Your story is pretty puzzling - it's tough to understand why you and your wife came to leave your children to go to dinner," Cuomo asserted, remarking that no American parent would "leave their kids in that way".

And yet, besides highlighting Madeleine's abduction on all four networked TV channels (ABC prefaced its coverage with clips of Britsofthe-moment J. K. Rowling and David Beckham making appeals for information, there were many other pluses.

Mr McCann visited a world-renowned centre for missing children, where he received advice and consoled himself with uplifting stories about abductions which ended fortuitously.

He lobbied senior statesmen on Capitol Hill, including U.S. Attorney General Alberto Gonzalez, who pledged to do all he could. He even met close aides to First Lady Laura Bush.

"Just about to go into the White House!" he texted his older sister, Philomena, 43.

Distraught: Kate is struggling to cope without her daughter

Missing: Madeleine McCann

Later, he told relatives how he received a sloppy, wet "kiss" from Mrs Bush's Scottish terrier, Miss Beazley.

"She must have known I was a fellow Scot," he joked.

For those who have followed the relentlessly miserable story of Madeleine's disappearance, Gerry McCann's lightening of mood this week - though probably brief - was heartening.

That said, however, watching him assume his unwanted ambassadorial role with such purpose and vigour, it was impossible to avoid contrasting his demeanour with that of his wife, Kate, who waited - forlorn, as ever - in the blisteringly hot Algarve.

For Madeleine's mother, the only white house that matters is the secluded villa in Praia da Luz, which has become the family's refuge since they escaped from Apartment 5A at the Ocean Club resort complex, a place of dark memories now occupied by other British holidaymakers.

Each morning, Kate returns to the scene of Madeleine's abduction to drop off her two-year-old twins, Shaun and Amelie, at the creche.

On Thursday, after she had settled them in, I happened upon her, walking down to the shore.

There she sat alone on the rocks, clutching Madeleine's pink Cuddle Cat toy as always, and gazing out at the Atlantic.

Later, she stopped briefly to pray at St Vincent's church, where the yellow ribbons tied to the door are fading.

Then she wandered back up the hill to the villa, a wraith among the throngs of cheerful tourists.

If her husband had manufactured a veneer of durability for the U.S. TV cameras, Mrs McCann's emotions were laid bare.

Thinner than ever, she has developed a stoop, as though the emotional burden she carries is strapped across her shoulders.

How was she bearing up, I asked tentatively, shaking her limp hand and wishing her well.

She forced a faint smile. "Yeah...well...thanks," were the only words she could summon.

Mr McCann's mother, Eileen, confirms the impression that 86 days after this highly publicised child abduction, Madeleine's parents are reacting in markedly different ways to their loss.

"Kate is really down; not one bit better than she was (when Madeleine was taken).

"I think she's actually going backwards," the 67-year-old widow told me from her home in Glasgow, where she has just returned after a fortnight at the Portuguese villa.

"All she keeps saying is: 'I need Madeleine back'."

"But Gerry is a lot better. He's thinking in terms of missing children.

"Madeleine is a missing child and so that's what he's focusing on. Everything he can do now is to help missing children, especially Madeleine."

When Mr McCann flew to Washington via London last Sunday night, his wife hugged him so tightly at the airport that it seemed she couldn't bear to let him go.

Reportedly, he phoned constantly from the U.S. to reassure her.

"She's a wee bit lost," said Eileen.

"I know Gerry misses Madeleine terribly and he would be over the moon if he got her back.

"But Kate, very much so. I just think it's a mother's instinct, isn't it? I just feel she needs a wee bit longer."

Eileen revealed that the couple suffered periodic feelings of guilt over the circumstances leading to Madeleine being snatched, but do not blame each other.

"How many people have stayed in their back gardens and put their children to bed?" she said."I think Kate is thinking along the same lines as me: that the person planned it carefully and watched what went on.

"They were just the unfortunate ones - Madeleine was picked out. All the family think that."

The McCanns believes the chief suspect, Robert Murat, still has a lot of questions to answer.

According to a Portuguese magazine yesterday, he has changed his alibi for the night Madeleine disappeared.

When first questioned, he is said to have told the police he was with his German girlfriend, but later said he'd spent the night at his mother's house.

While the investigation continues, the McCanns are in limbo.

Gerry, who is on unpaid leave from Glenfield Hospital, Leicester, has spoken about returning to Britain.

But his 39-year-old wife, who is on leave from the GP practice where she worked two days a week, refuses even to countenance leaving Praia da Luz.

Whenever the subject is broached, her response is always the same. "I'm not going home without Madeleine."

According to Philomena McCann, neither her brother nor sister-in-law enjoys being in the public eye.

But Kate feels particularly uneasy and will put herself forward only if she believes it is essential to further her cause.

However, as Gerry is accustomed to addressing audiences at medical conferences, he is far more comfortable in the spotlight.

He has become the public face of the campaign (including receiving calls of support from Gordon Brown) while his wife remains in the background.

"I'm incredibly proud of my brother when I see how he's handling this. But what people see is Gerry being really strong in front of the cameras," said Philomena.

"They don't see the really awful times, and nobody is going to let them see that."

For 12 weeks, Kate has been supported by a rota of visiting relatives.

Her sister-in-law Tricia Cameron, a redoubtable nurse who cooks wholesome meals and raises her spirits, has left her only once for a brief visit to Cambridge to see her son, Paul, graduate in medicine.

Any day now, though, even Mrs Cameron and her teacher husband, Sandy, must say goodbye. But Kate has arranged for replacements to fly in.

Should anyone suggest gently that she could be more easily supported at home in Leicestershire, she explains that she "must be at the scene of the police investigation the very second news breaks".

"I suppose any mother would feel like that," says her mother-in-law.

"But she's got to go home some time. We are hoping that over the next few weeks, Kate will start thinking about it in the longer term.

"But I know for definite that she won't come back at the moment."

So, this could turn out to be a watershed week for the McCanns, with Gerry making strides towards a deliverance of sorts through campaigning work, while Kate retreats further into the depths of her anguish.

Perhaps not entirely coincidentally, this shift comes at the time when, in some quarters at least, the tide of goodwill for the couple is beginning to take a disquieting turn.

From the moment Madeleine went missing, a small section of the public criticised the McCanns for dining in a tapas bar 50 yards from the room where their children slept.

They checked up on them every half-hour rather than make use of the Ocean Club's baby-sitting service.

This week, however, what began as reproach became open hostility.

It appears to have been whipped up by a series of dubious 'investigative' articles in the new Portuguese weekly newspaper Sol, which have found their way on to the internet.

Cruelly, and with scant substantiation, the paper portrays the McCann holiday party as more interested in playing tennis, and wining and dining, than looking after their children.

It also accuses the group of maintaining a pact of silence about the events on the evening of May 3, and purports to have uncovered a link between Robert Murat and one of the couples holidaying with the McCanns - they come from Exeter, where Murat had visited his sister a few days before the abduction.

As the Portuguese police investigation has been widely criticised, these salacious articles may have been motivated by misplaced nationalistic revenge.

But it seems someone at the heart of the inquiry was involved - they contain names and details not previously published.

Whatever the truth, understandably the McCanns are wounded, particularly Kate, whose mistrust of the media has been bitterly confirmed.

They have been stung, too, by other accusations which are so callous that their local paper, the Leicester Mercury, was compelled on Wednesday to block its on-line message facility for the couple.

There have been calls for them to be prosecuted for neglect.

Madeleine's case is also said to have been given unwarranted attention because her parents are middle class and have run a slick PR campaign.

Some even suggest they stand to gain from the money donated by the public.

All of these slurs are as preposterous as they are disgraceful.

This week, however, when I spoke to Philomena, she felt compelled to defend her brother and sister-in-law.

"People talk about Team McCann - they think it's orchestrated. That's nonsense. It's bits and pieces, and pals pulling together," she said.

"There hasn't been any kind of cynical campaign. It's just an amazing coming together. We've winged it and learned as we've gone along."

She cited the Find Madeleine website, with its haunting footage, Gerry's daily blog, an on-line store selling yellow bracelets for a £2 donation and a diary of forthcoming events, all set to the Bryan Adams song (Everything I Do) I Do It For You.

Remarkably professional looking, it was created by 19-year-old Callum McCrae, one of Philomena's former pupils.

Then there was the Look Into My Eyes poster, inviting people to memorise the distinctive 'flash' in Madeleine's right eye.

That was devised by Jon Corner, a friend who runs a media company in Liverpool.

Another friend, Michael Wright, a businessman from Skipton, uses his network of contacts to get funding, and Gerry's brother, pharmaceutical company rep John McCann, helps with strategy.

Madeleine's face is instantly recognisable in dozens of countries, and the reward for information leading to her return stands at £3.2 million.

"It needs only one greedy, unscrupulous character to come forward," said Philomena McCann.

"So the campaign will go on, whatever anyone says. Those who say we just want to appear on telly should get a life. Can you imagine stopping looking for your daughter?"

Already plans are in place for the next big showpiece event, to mark the 100th day of Madeleine's disappearance on August 11.

Assuming she has not been found by then, 100 Scottish pipers will play a tune penned for her at the world pipeband championship in Glasgow.

Well-intended as such efforts are, of course, one danger is that compassion fatigue will set in.

Indeed, judging by the turn of events this week, that may already have happened.

Alex Woolfall, a public relations expert who represents Ocean Club's owners, Mark Warner, and maintains contact with the McCanns, says he warned them about this from the beginning, but adds: "Who are we to judge? We haven't been in their position."

However, according to Ray Wyre, an expert on paedophilia who advised detectives on the Fred and Rose West murder investigation, the decision to keep Madeleine at the top of the news agenda could have serious ramifications.

"There are two potential scenarios," he told me. "If you are Madeleine's parents, it is understandable to want publicity because it might bring information.

"And it means you are not dealing with bereavement; you are dealing with a lost child.

"On the other hand, if Madeleine is in captivity, a high-profile campaign could make her position even worse.

"Her captor may feel it necessary to shut her away for longer periods to avoid her being recognised.

"There's also the possibility that the abductor - or killer - may be watching the McCanns and getting kicks out of what they are doing.

"If you are dealing with a sadist, publicity can become part of the problem. As awful as these possibilities are, they should be assessed carefully."

Since the McCanns are receiving psychological help, these risks must have been taken into account.

Mr Wyre also expressed a concern that, as in so many cases of family trauma, the strain of losing Madeleine might adversely affect the twins and cause cracks in the McCanns' relationship.

Happily, in this regard at least, Gerry McCann's mother has no fears.

"I know a lot of people split up in situations like theirs, but no way," she said.

"Gerry adores Kate, and she adores him. They were very much in love before, and they still are. I can see in their manner towards each other that it's still there.

"They are saying that all that matters is the twins until they get Madeleine back.

"They spend more time with them than ever. Kate is there at bath-time, lunch-time, dinner-time and bed-time. At the beginning, she wasn't able to do that."

Though the family are careful to avoid saying anything distressing relating to Madeleine, she is discussed as normally as possible in front of Shaun and Amelie.

"Every night, before going to sleep, they always say the same thing: 1Good night, Shaun. Good night, Amelie - and good night, Madeleine,'" said Eileen.

This touching family ritual is something the hate campaigners would do well to remember as they turn on Gerry and Kate McCann - a devoted father and mother, each struggling to survive through every parent's worst nightmare in their own, very individual way.