What the home secretary does is to give himself the power to direct at every level the operations of every police force in England and Wales

Oliver Letwin Shadow home secretary

Lord Strathclyde unveiled his party's stance on Thursday as peers were set to debate the committee stage of the bill.

Under the procedure rules, the government cannot steamroller it into law if peers defeat the will of ministers, because the bill began its passage through parliament in the Lords.

Crucial votes

Conservatives believe they can win the backing of Liberal Democrats, rebel Labour peers and crossbenchers to defeat the government in the Lords over the home secretary's powers.

Crucial votes will take place after Easter during the report stage.

Lord Strathclyde told reporters: "We yield to no one in our desire to remove crime from the streets of this country. Our record stands for itself.

"But there is one issue more important than any other, which is the ability for the home secretary to control every police force in the country.

Lord Strathclyde is hoping to rally peers against the plans

"Our aim is to stop him from doing so and we are busy building up an alliance of Labour backbenchers, crossbenchers, Liberals and of course Conservatives in order to do that.

"We will do what the House of Lords always does in these circumstances, which is to stand up for natural justice and common sense and get the home secretary to re-think his policy on this when it returns to the Commons some time at the end of April or the beginning of May."

Shadow home secretary Oliver Letwin said many of the Bill's aims were very welcome but two sections of it "pose a fundamental threat" to the rule of law in Britain.

"What the home secretary does is to give himself the power to direct at every level the operations of every police force in England and Wales."

Mr Letwin said the problem was there was no evidence the Home Office was any better than anyone else at running things.

It was responsible for the Immigration and Nationality Directorate, "one of the least well functioning bureaucracies in the history of Britain", said Mr Letwin.

Fighting talk

He said even Mr Blunkett had described the asylum system as "chaos", while the prison system was failing the country with huge reoffending rates.

Mr Letwin added: "No doubt, there are many admirable, intelligent, hardworking people in the Home Office, but collectively they have not demonstrated a colossal efficiency compared with our police forces."

"The reason we will fight until the last ditch is that the fundamental bastions of our liberties under the rule of law are the courts and the operation of the independence of the police force."

Mr Letwin said he had no doubt that David Blunkett was well-intentioned, but he was being careless about the long-term effects of measures taken now.