Women rescued from sex slavery by a new police operation could still face the risk of deportation, Home Secretary Jacqui Smith said yesterday.

The politician insisted the Government was unable to give a guarantee that none of the illegally smuggled victims would be removed, but renewed a pledge to give them a reflection period of 30 days.

The news came as police across the UK and the Republic of Ireland launched the second wave of an operation designed to crack down on the trade in enforced prostitution.

Three women have already been rescued by officers in Operation Pentameter since work began on Monday, said Association of Chief Police Officers spokesman and Gloucestershire Chief Constable Dr Tim Brain.

The Home Secretary said she shared concerns that British men who use prostitutes have helped to drive demand for criminal smuggling of women and girls.

But she added that she did not support a change in the law to criminalise prostitutes' punters.

On whether victims would face deportation, she said: "I'm not going to give an across-the-board guarantee that nobody who is a victim of trafficking would be removed back to their source country."

Ms Smith said she hoped Government officials who decide asylum cases would fully take into account any traumatic experiences women rescued by Pentameter or other police operations might have suffered in forced prostitution.

Asked whether she supported criminalising men who use prostitutes, the Home Secretary said: "While we are not formally reviewing it at the moment I share some of the concerns about the demand for prostitution.

"We are not undertaking work at the moment, but that doesn't mean that we won't do."

She added: "Operation Pentameter will send out a clear message that as a society we won't tolerate the exploitation and brutality perpetrated by these 21st Century slave traders."

The second Pentameter operation, which follows a four-month project last year, will seek to build a comprehensive picture of sex trafficking in the British Isles, with a focus on helping victims, he said.

Police forces in the North-East and North Yorkshire are all involved in the operation.

A spokesman for Durham Police said: "Our involvement at the moment is mainly in gathering intelligence to assess the scale of the problem if there is one."

A spokeswoman for Cleveland Police said they would also be contributing information, while a North Yorkshire Police spokeswoman said the force had signed up to Pentameter but had nothing specific planned at this time.

The director of Anti-Slavery International, Aidan McQuade, welcomed the launch of Pentameter, but said it was unfortunate that a law change from three years ago allowing people to be prosecuted for forcing others to work as slaves in non-sexual tasks had still not led to a conviction.

"It is 200 years since the British abolition of the transatlantic slave trade and it is a shame that we are still talking about slaves within this country," he said.