Downing Street today said there were no immediate plans to import a US law giving parents access to information about paedophiles in their area as it sought to play down speculation fuelled by home secretary John Reid.
Mr Blair's office toned down comments made by Mr Reid over the weekend as he promised to consider a British version of the controversial Megan's Law in America, under which parents are given full details of child sex offenders released into their neighbourhood.
The prime minister's official spokesman said today: "Everybody understands the genuine difficulties in this area. There is genuine concern in communities about this kind of justice and it's right and proper that the home secretary takes account of these genuine concerns.
"What has changed is that we are actively looking at how we can give more information to the public."
Megan's Law was introduced across the United States nine years ago and ensures parents are told when a released child sex offender moves into their area. It was introduced across all 50 states after the rape and murder of seven-year-old Megan Kanka by a known paedophile.
Speculation mounted that similar measures could be under way in the UK after 70 paedophiles were unexpectedly moved out of 11 probation hostels close to schools across England and Wales over the weekend amid warnings this could jeopardise plans to keep them under supervision.
The Home Office said hostels for released prisoners near schools would now operate a restricted admissions policy excluding sex offenders.
Mr Reid also announced he was sending his prisons minister, Gerry Sutcliffe, to the US to look at the implementation of Megan's Law in different states and work out the best way of ensuring the controlled release of information to the public. "Information should no longer remain the exclusive preserve of officialdom," he said.
Since the death of eight-year-old Sarah Payne in 2000, the News of the World has led a six-year campaign to name and shame paedophiles and publish the addresses of all 101 probation hostels that house offenders, sparking fears of vigilante attacks and warnings that paedophiles were going underground.
In some US states, offenders' details are listed on the internet, allowing parents to check if anybody has moved in nearby, while in Oregon sex offenders can be forced to display a sign in their window.
But critics say that as a result of Megan's Law only 80% of released offenders comply with registration requirements in the US, compared with 97% in Britain.
Senior probation source have also warned that "controlled access" by parents and schools to the home addresses and other personal details of released child sex offenders could lead to "lynch mob law".
Downing Street played down the prospect of the law being carbon-copied to the UK as it highlighted the "genuine difficulties" of releasing more information to the public on the whereabouts of paedophiles.
The prime minister's spokesman said: "The important thing and the difficult thing in this is to get the balance right between, on the one hand, protecting the public and giving the public as much information as possible, and on the other making sure that you don't have vigilantes.
"What's important is that Gerry Sutcliffe goes to the US and looks at how they do things there. We are not planning immediately to import US laws but we do need to consider how these operate.
"It is sensible to take a fresh look at this to see if there is a way of balancing two conflicting needs and demands and take account of the experience that has been acquired elsewhere. What is clear is that this is an issue of public concern that isn't going to go away."
Mr Reid is the first home secretary since the murder of Sarah Payne by the released paedophile Roy Whiting to concede that the names and addresses of released sex offenders should be circulated beyond the police and probation staff.
At present the multi-agency public protection panels that decide on how released paedophiles should be supervised inform parents and schools on a strict "need to know" basis.
The shadow home secretary, David Davis, said he backed the government's approach but it needed careful consideration: "We must also make sure we don't end up with some lynch mob law."
Harry Fletcher of Napo, the probation union, said there was no evidence that sex offenders in hostels had preyed on children in local schools. "Virtually all hostels are in residential areas. The advantage of a hostel is that we can maximise supervision and moving them to different locations can jeopardise those plans. They will be in therapy programmes that are going to be disrupted," said Mr Fletcher.
The tougher attitude towards released sex offenders comes as Mr Reid has to make some difficult decisions about how to cope with overcrowding in prisons. This month he is due to publish detailed plans for the 139 prisons in England and Wales that were supposed to incorporate Charles Clarke's promised move towards community prisons. But it is believed that Mr Reid has already ruled out a programme of "administrative release" of less serious offenders to create more space.
Instead, plans for a new "custody plus" sentence to be introduced in November, which would have removed tens of thousands of short-sentence inmates from prisons, have been postponed because the probation service does not have the capacity to deal with them.
The former home secretary, Jack Straw, said yesterday that more prison places were needed, and the chief inspector of prisons, Anne Owers, warned that the 139 prisons in England and Wales were close to putting up "house full" notices.
After a fortnight of intense political debate over sentencing, the prison population, which is now rising by 148 a week, hit a record of 77,785 on Friday - with room for only a further 1,715 inmates. "We are looking at a system where prison numbers are rising inside what is already a hugely pressured area. That may hit the buffers soon at a point where there are not any more spaces," warned Ms Owers.
"I think the point will come at which prisons have to put up 'house full' notices."
The Conservatives yesterday promised to build more prisons, paid for by ditching the national identity card scheme due to be introduced from 2008.
At Commons question time today, Liberal Democrat home affairs spokesman Nick Clegg warned that registration of sex offenders who posed a continued threat to children was only 30% in some American states. In the UK the equivalent figure was "well over" 90% on the sex offenders' register, he said.
And he cited a 2001 warning by then home office minister Beverley Hughes that making information about sex offenders widely available would hinder child protection by driving some of the worst offenders underground.
"If that is the case why is it now that the government seems to be revisiting an idea which has been so summarily rejected by ministers before?" he demanded.
Junior home office minister Vernon Coaker said the government was considering all of these matters: "The aim of this Government is to tackle access to child pornography on the internet, to tackle sex abuse, to tackle sex offenders. We will do all of that and we will come up with the best policies to do so."
British Home Secretary John Reid has met criticism from several quarters for his suggestion that the UK should adopt a law allowing the public naming of known paedophiles.

The United States has legislation known as 'Megan's Law' which Reid has suggested should be adopted. Such a law would allow concerned parents to access information regarding paedophiles in their area. Gerry Sutcliffe, a Home Office Minister, has been sent to the US to investigate whether a similar system could be introduced.

A spokesman for Prime Minister Tony Blair issued a statement on comments Reid made over the weekend, "the important thing and the difficult thing in this is to get the balance right between, on the one hand, protecting the public and giving the public as much information as possible, and on the other making sure that you don't have vigilantes".

The spokesman denied that there were immediate plans to adopt Megan's Law, "What's important is that Gerry Sutcliffe goes to the US and looks at how they do things there. We are not planning immediately to import US laws but we do need to consider how these operate".