DAVID Cameron and his Conservative ministers have come under fire from their Liberal Democrat Coalition colleagues for launching a "stupid and offensive" crackdown on illegal immigrants.

The broadside from Vince Cable, the Business Secretary, came as MPs said official immigration statistics as no better than guess work.

Mr Cable said Immigration Minister Mark Harper's decision to send vans with the message "go home or you'll be picked up and deported" around London was to create public fear .

He rubbished "misleading" targets to reduce net migration and insisted Britain did not have a vast problem with illegal immigrants.

The Secretary of State made clear LibDem ministers had not been consulted about the van campaign, saying: "It was stupid and offensive. It is very unlikely it will continue."

Mr Cable said: "It is designed, apparently, to sort of create a sense of fear (in the) British population that we have a vast problem with illegal immigration. We have a problem but it's not a vast one. It's got to be dealt with in a measured way dealing with the underlying causes."

Labour denounced the van campaign as a "short-sighted and foolish" gimmick and a Tory attempt to win over UKIP vote; campaigners denounced it as racist.

The Commons Public Administration Committee said official migration statistics were "not fit for purpose" and said assessments of the UK Government's progress in reducing net migration to below 100,000 a year as "little better than a best guess".

But the Home Office disagreed, claiming statistics showed net migration is at its lowest level for a decade. "The Government is determined to build a fairer system and to address the public's concern about immigration," a spokesman said.