David Blunkett is under fresh pressure amid reports that the government ordered a non-arrest policy for illegal immigrants in order to meet the prime minister's target of reducing asylum numbers.

Sunday newspapers suggest the policy was ordered by ministers following fears that confronting illegal immigrants - some who would have been criminals - would have resulted in them seeking asylum.

The reports come as the prime minister called together senior ministers and security chiefs for an emergency summit on Tuesday.

Scam leaks

The Tories say a welter of leaks from government departments have revealed a pro-active policy of allowing illegal migrants to remain at liberty.

David Davis, the shadow home secretary who last week claimed the scalp of Beverley Hughes, said the policy amounted to a "public scandal".

Meanwhile the Sunday Telegraph claims that the prime minister personally struck a deal with his Romanian counterpart under which the visa system would have been removed by this Spring.

It is reported that Blair told Adrian Nastase that Romanians seeking to come to the UK would not need to seek a visa.

Number 10, however, has denied that the move formed part of an orchestrated attempt to reduce the pool of would-be asylum seekers in order to meet the prime minister's pledge to achieve a 70 per cent reduction.

"There is no question here of a deal or trade-off. We are working very hard with the Romanian government to stop illegal immigration and to get to a point where visas are no longer necessary," said a Downing Street spokesman.

Inquiry call

But opposition parties are using the Sunday newspaper claims to call for a full public inquiry into the immigration system.

David Davis said an "independent investigation" outside of Home Office control was now required.

"If the problem is more widespread, then the home secretary is accountable. But of course, it may well be that the home secretary is simply doing the bidding of the prime minister to try to meet these headline targets he keeps throwing up," he told Sky News.

The Liberal Democrats are also repeating their demand for a full public probe.

The party's leader Charles Kennedy said: "There's no point Tony Blair having a much-publicised summit and talking about a tougher approach and all the rest of it if he's not willing to get to the heart of the matter.

"Fairly or unfairly, the Hutton Inquiry satisfied very few, the Butler Inquiry is unlikely to satisfy very many and an internal inquiry will satisfy no one at all."