Prime Minister Tony Blair (search) said Sunday he had not expected the ferocity of the insurgency in Iraq, but he insisted British troops would stay as long as the Iraqi government needed them.

As Blair's governing Labor Party (search) gathered for its annual conference, the prime minister said he had not set a deadline for withdrawing some 8,500 British soldiers from Iraq.

"There is no arbitrary date being set," he said, in an interview with the British Broadcasting Corp.

But Defense Secretary John Reid (search) said British troops could begin handing over their responsibilities to Iraqi soldiers and police next year.

Blair also insisted that two British soldiers rescued from an Iraqi jail last week would not be handed over to Iraqi authorities.

The two soldiers, operating undercover, were arrested Monday in southern Iraq after allegedly shooting two Iraqi policemen who tried to detain them. A British armored patrol surrounded the jail in Basra where the two were held and crashed through the prison walls to rescue them.

The British patrol were attacked by angry locals hurling Molotov cocktails and stoning soldiers as they fled from their burning vehicle.

"We will do whatever is necessary to protect our troops in any situation," Blair told the BBC.

Asked if Britain would accept arrest warrants for the soldiers, Blair responded: "No, absolutely not."

Images of the British soldiers jumping from armored vehicles with their clothes on fire thrust Iraq back into the British media spotlight and reignited criticism of the way Blair has handled the conflict.

The opposition Liberal Democrats have stepped up demands for British troops to withdraw -- a call backed by some in Blair's own party.

Blair was asked whether he had expected it to be so difficult to restore order to Iraq following the U.S.-led invasion.

"No, I didn't expect quite the same sort of ferocity from every single element in the Middle East that came in and is doing their best to disrupt the political process," he said, referring to insurgents who have flooded into Iraq from neighboring countries such as Syria and Iran.

"But I have absolutely no doubt as to what we should do. We should stick with it."

Reid dismissed a report in The Observer newspaper that Britain was drawing up detailed plans to begin leaving Iraq in May, telling Sky News that would only happen when Iraqi forces were ready to take over security responsibilities.

"When that condition has been met, we will hand over the lead in counterterrorism to the Iraqis," Reid said.

"There will then be a process -- it won't happen overnight -- where they gradually take the lead, we gradually withdraw to barracks and we gradually withdraw from Iraq itself. At that stage, when the conditions have been met, we will withdraw.

"And I said that is possible to start in some parts of the country, that handover, in the course of next year."

On the domestic side, Blair wants to use the conference in the southern coastal town of Brighton to rally the party behind his program of reforming public services.

But he faces the perennial challenge from trade unionists and left-wingers in the party, who oppose his plans for greater private sector involvement in state-run education and health care.

The government also faces demands to overhaul state-funded pensions, which are in crisis due to an aging population, and repeal employment laws passed by former Conservative Prime Minister Margaret Thatcher that curtail the rights of unionists to strike.

The union motions cannot force the government to alter policy, but defeats would prove embarrassing for Blair.