David Blunkett has defended the prime minister's pledge to slash the number of asylum seekers after a senior Labour MP warned it would "end in tears".

The home secretary said the government would stick to its "firm commitment" - announced in a television interview - to halve asylum claims by September.

But Labour MP Chris Mullin cautioned against "becoming impaled on any more unrealistic targets".

Mullin's remarks were seen as an implicit rebuke to Tony Blair following his pledges on asylum.

"What is needed is clear, consistent progress, baring in mind all the complexities which surround this subject, and not a big bang which will inevitably end in tears," said the chairman of the home affairs committee.

Blunkett said he would "take the advice to heart" and praised the backbencher as "a very wise counsel".

The home secretary also launched another strong attack on the judges who blocked tough new benefits rules aimed at cutting the numbers arriving in Britain.

Last week the High Court blocked government measures which strip late claimants of their right to claim housing and food benefits.

Senior judge Mr Justice Collins backed the asylum seekers, describing the new rules as "inhumane".

The home secretary said he intends to appeal against the decision, and told MPs on Monday that he would not back down.

"I accept entirely that it is right for judges to be able to use judicial review to facilitate challenges to government where they think that they have acted in an administratively inadequate fashion," Blunkett said.

"But I do not accept that judges have the right in this country to override the will of his House, or our democracy, or the role of MPs in deciding the rules."

Shadow home secretary Oliver Letwin said the current asylum system should be scrapped and be replaced by a "rational" system of quotas.

He warned ministers against meeting their asylum targets by the "statistical manipulation" of issuing work permits to people who would otherwise claim asylum.

Former Home Office minister Ann Widdecombe accused the government of abandoning targets on the removal of failed asylum seekers.

Blunkett slammed her "breathless audacity" arguing that she had presided over a system which achieved half as many removals as Labour.