Stubborn Home Secretary Theresa May refused to apologise to MPs yesterday after she was forced to call time on hateful patrols by "go home or face arrest" vans aimed at immigrants.

Ms May told the Commons that the ad vans had proved "too much of a blunt instrument."

Officials had earlier confirmed that the Home Office did not intend to roll out the campaign nationwide after an evaluation.

Shadow Home Secretary Yvette Cooper looked across at Ms May and demanded: "Will you now apologise for the divisive ad vans that she has now admitted have been a serious problem?"

But amid Labour taunts, Ms May stayed silent on the government front bench.

"I hope she is ashamed of what she did," added Ms Cooper, who claimed that just one person had rung the phone number asking to leave Britain.

Widespread complaints followed deployment of billboards carried by vans touring six London boroughs where a relatively high number of ethnic minority residents live.

Liberal Democrat Business Secretary Vince Cable described the campaign as "stupid."

The Advertising Standards Authority (ASA) ruled against the campaign earlier this month on the grounds that it was using misleading arrest statistics.

Vans bore advertising billboards reading "In the UK illegally? Go home or face arrest." They also bore a claim of "106 arrests last week in your area."

But the ASA rejected complaints that it was offensive and irresponsible.

The ASA received 224 complaints, including groups representing migrants and legal academics.