The Shadow Home Secretary Ann Widdecombe has called for the police to be allowed to "do their job" amid speculation that a fall in the use of stop-and-search powers is linked to a rise in street crime.

Ms Widdecombe's warning came as figures revealed the first rise in offences in England and Wales for six years, including a rise in violent crime in urban areas.

Prime Minister Tony Blair was also holding his first meeting with the incoming Commissioner of the Metropolitan Police in London, Sir John Stevens, who takes over as the head of UK's most high-profile force in a fortnight.

Ms Widdecombe told the BBC that while there was no hard evidence linking fewer stop-and-searches with rising crime, police officers had told the party of their fears.

"What I am particularly interested in is street crime," she said. "There are a lot of questions about whether or not the police's unwillingness to engage in stop-and-search has actually led to a rise in crime."

Ms Widdecombe said that the latest crime figures would help experts to identify whether there was a link.

Controversial weapon

Police forces who make use of stop-and-search powers have often found themselves at the centre of controversy.

Some forces, including the Metropolitan Police, have been accused of stopping and searching disproportionate numbers of young black men in the street or in their cars.

Campaigners say the use of the searches is a symbol of institutionalised racism in the British police.

In their defence, the police say that they have learned lessons from the MacPherson Report into the Stephen Lawrence murder investigation and that the use of stop-and-search can be a valuable weapon in the fight against crime.

Some officers also predict that proposed legislation to extend race relations provisions to the police force, recommended by Lord MacPherson, will lead to the end of stop-and-search because officers will fear prosecution for racial discrimination.

Ms Widdecombe added: "The police must be able to their job. Everyone understands the enormous caution that arose in the wake of the report into the death of Stephen Lawrence.

"But the police must be able to carry out their functions and stop-and-search people or cars without automatically ending up in the wrong and in a disciplinary procedure."