The parents of murdered Soham girls Holly Wells and Jessica Chapman have been

Cambridgeshire Police confirmed that Met detectives visited the parents of the murdered girls

ANALYSIS Iain Watson Political correspondent, BBC News   Calls for tougher press regulation are nothing new. In the 80s the Tory minister David Mellor warned some editors were "drinking in the last chance saloon". But last orders still haven't been called. Then ministers opted for a system of self-regulation by the press. There's a general rule that oppositions urge tighter regulation but fail to implement it in government. Although newspaper sales are in decline, politicians still seek their endorsement. Unlike broadcasters, the press are free to be politically partial and the Murdoch press control around a third of the market. They endorsed Labour in 1997 - ex-Downing Street insider Lance Price has said no big decision was taken without considering Rupert Murdoch's likely reaction. After two parliamentary inquiries, in 2007 Labour declared the system of self-regulation was still "appropriate". Former News of the World editor Andy Coulson was David Cameron's communications chief until early this year. At the last election, the Murdoch tabloids switched allegiance from Labour to Conservative. Labour are now taking a tougher line saying it is time to "clean up the press" - although some senior voices worry they should not be alienating powerful proprietors. Sources close to Culture Secretary Jeremy Hunt suggest he might support a public inquiry into the media once police investigations conclude. So closing time could come to the last chance saloon after all.

Schoolgirl Milly Dowler's remains were found six months after she went missing in March 2002

 visited by police investigating phone-hacking by journalists.

Private investigator Glenn Mulcaire, working for the News of the World, allegedly hacked the phone of murdered girl Milly Dowler when she was missing.

News International has promised the "strongest possible action" if it is proven Milly's phone was hacked.

In a statement, Mulcaire apologised to anyone "hurt or upset" by his actions.

Jessica and Holly, both 10, of Soham, Cambridgeshire, were murdered in 2002 by school caretaker Ian Huntley, who was jailed for life.

BBC business editor Robert Peston says police are investigating whether the phone of Jessica's father, Leslie Chapman, was hacked by the press.

Our business editor says that, in relation to the phone-hacking claims involving Milly, News International executives privately say they accept that the basic allegations are true.

"Perhaps more striking, however," he adds, "is that those executives also say that there may be even more embarrassing revelations to come about the way that News of the World journalists obtained information about other individuals."

Milly, who was 13, went missing in March 2002 near her home in Walton-on-Thames, Surrey. Her remains were found in remote woodland at Yateley Heath in Hampshire six months later.

Nightclub doorman Levi Bellfield was convicted of the murder last month.

The Guardian has claimed Mulcaire intercepted messages left by relatives for Milly while she was missing and that the News of the World (NoW) deleted some messages it had already listened to in order to make space for more to be left

In a statement released to the Guardian on Tuesday, Mulcaire made no direct reference to those allegations but apologised "to anybody who was hurt or upset by what I have done".

He said: "Working for the News of the World was never easy. There was relentless pressure. There was a constant demand for results.

"I knew what we did pushed the limits ethically. But, at the time, I didn't understand that I had broken the law at all."

He added that he "never had any intention of interfering with any police inquiry into any crime".

BBC Newsnight has learned that police investigating press phone-hacking have also spoken to Jacqui Hames, a former Met officer and presenter on BBC's Crimewatch, and Clarence Mitchell, spokesman for the family of missing child Madeleine McCann.

Mr Mitchell told the BBC that someone had tried to persuade his mobile phone network operator to reveal confidential information about his account.

Meanwhile, Channel 4 News has reported that Dave Cook, a Metropolitan Police detective, was put under surveillance by News of the World journalists.

'Further torture'

In a memo to staff on Tuesday, Rebekah Brooks, chief executive of NoW publisher News International, said the allegations Milly's phone was hacked were "almost too horrific to believe".

"I have to tell you that I am sickened that these events are alleged to have happened," Mrs Brooks wrote.

"Not just because I was editor of the News of the World at the time, but if the accusations are true, the devastating effect on Milly Dowler's family is unforgivable."

She added: "I hope that you all realise it is inconceivable that I knew - or worse - sanctioned these appalling allegations."

Labour leader Ed Miliband said the public would be "horrified that the grieving parents of an abducted child were made to go through further torture that somehow she was alive because her voicemails were being retrieved or deleted".

He called the allegations a "stain on the character of British journalism", adding there should be "a proper inquiry into the culture and practices which allowed these things to happen".

Motor company Ford has announced a halt on advertising in the News of the World, pending the newspaper's investigation and response over the phone-hacking claims.

"Ford is a company which cares about the standards of behaviour of its own people and those it deals with externally," it said in a statement.

Energy company Npower and the Halifax bank have announced they are considering their options regarding advertising in the News of the World.

MPs will hold an emergency debate on Wednesday on whether there should be a public inquiry into the phone-hacking scandal.

House of Commons Speaker John Bercow granted the urgent debate following a call by Labour MP Chris Bryant, who accused the News of the World of "playing God with a family's emotions".

In the upper house, former Conservative Party Chairman Lord Fowler said an inquiry was needed in the wake of "one of the biggest scandals affecting the press in living memory".

Out-of-court settlements

Home Office minister Baroness Browning said the government would await the outcome of the police investigation before deciding whether further action was necessary.

Also on Wednesday, the Media Standards Trust - which aims to promote high news standards within the media - will launch the Hacked Off campaign calling for a public inquiry into "phone hacking and other forms of illegal intrusion by the press".

On BBC Radio 4's World at One programme, actor Hugh Grant - who investigated hacking for the New Statesman in April - said that he hoped the latest allegations would bring about a public inquiry.

It had previously been difficult to get people to care about the hacking scandal - which involved celebrities and MPs having allegedly been targeted - because "most victims are rich", Mr Grant said.

"It's been hard to get people to viscerally feel sickened and outraged, but now that people fully realise just how repulsive these people are - and the lengths to which they'll go - hopefully there'll be more momentum in getting something done," he said.

The Metropolitan Police launched Operation Weeting in January this year after new phone-hacking claims emerged. The force has faced criticism for its initial inquiry in 2006 into phone-hacking at the paper.

That probe led to the convictions and imprisonment of Mulcaire and then News of the World royal editor Clive Goodman in 2007 for conspiracy to access phone messages left for members of the royal household.

A number of alleged phone-hacking victims have since reached out-of-court settlements with the newspaper