Blunkett is accused of manipulating falling figures

David Blunkett faced accusations of fiddling the figures yesterday after the Government announced that the number of refugees claiming asylum was plummeting.

Tony Blair hailed the statistics as proof that Britain had "turned the corner" on a problem that has bedevilled ministers since Labour came to office. Mr Blunkett revealed that the Government was planning fresh initiatives against abuses of the asylum system.

But Oliver Letwin, the shadow Home Secretary, warned there were "serious doubts" over the authenticity of the figures, while human rights groups accused the Government of putting too much emphasis on targets. Last autumn, the Prime Minister pledged that the monthly total of asylum applications would be halved, to 4,450, by September this year.

Home Office data said yesterday that the numbers had fallen by 32 per cent in the first quarter of the year, compared with the previous three months. The monthly totals were 7,175 in January, 4,255 in February - the lowest for four years and below Mr Blair's target - and 4,565 in March.

The Government hailed the falls as proof that a series of policies was beginning to bite. These changes included a clampdown on entitlement to benefits, the closure of the Sangatte transit camp near Calais, tighter security around the Channel Tunnel and the extension of the number of "white list" countries, whose asylum-seekers are rapidly returned with no right of appeal.

Mr Blair said: "The figures published today by the Home Office show we have turned the corner." He added that reports sent to him weekly showed figures were "continuing to improve". He said: "We remain fully on track to meet our pledge to cut applications in half by September. It's obviously a long haul but we will continue to keep up the pressure."

But Mr Letwin suggested "some form of manipulation" could have affected the headline figures. He said: "I seriously doubt the measures taken could have had such a rapid effect. The big question is whether there are other factors we have not been told about."

The Tories said that a rise in the number of work permits issued to foreign nationals - now running at about 120,000 a year - could have driven down the headline figure.

A furious Mr Blunkett retorted: "If they continue to claim we have somehow fiddled the figures, I will publicly describe them as liars and I will invite them to sue me because I think the credibility of the statistics is absolutely vital."

A spokesman for Mr Blunkett added: "Oliver Letwin was more than happy to accept the figures when they were at record levels. But now he's scrabbling around for reasons why he can't accept the way they are calculated once they are going down."

However, Keith Best, chief executive of the Immigration Advisory Service, said the Government's new measures might have encouraged people to enter Britain clandestinely. He said: "The Government has made it so unpleasant for people to claim asylum but they will still seek to come here."

The Home Secretary also revealed a three-pronged plan that would tackle abuses of the asylum system.

Measures to streamline the appeals process for asylum-seekers whose claims have been rejected and to make it harder for those who destroy travel documents to win asylum are being drawn up. A crackdown on abuse of the legal aid system is also planned.

Margaret Lally, acting chief executive of the Refugee Council, said: "We are very concerned that government measures, like visa restrictions on Zimbabwe, are preventing people whose lives are in danger reaching safety.

"A reduction in asylum numbers is hollow and meaningless if those affected are people fleeing persecution."

Kate Allen, the director of Amnesty International UK, said: "People should come before targets. The government's current obsession with asylum number-crunching risks obscuring the fact the real issue is not whether or not we can get the numbers down but whether we can offer protection to the world's tortured and persecuted ... Setting artificial targets was always misguided and suggested the Government was more concerned with headlines than dealing responsibly with those fleeing persecution."

Removals of failed asylum-seekers were marginally down, to 2,620 in the first three months of the year, but that was up 7 per cent year-on-year.

Of 20,765 initial decisions made by immigration officers, 5,490 principal applicants were either granted asylum or "exceptional leave" to remain in the UK. That amounted to 26 per cent of decisions, compared with a monthly average of 34 per cent given permission to stay here during 2002.