Fifty-three Labour MPs rebel despite Blair's assurance: 'Our purpose is No one wants military conflict'

Tony Blair suffered a substantial protest vote from his own backbenchers last night over a possible war with Iraq, despite trying to reassure MPs that his goal was to remove Saddam Hussein's weapons and not to topple him.

Fifty-three Labour MPs voted against the Government at the end of an emergency one-day debate in the second biggest backbench rebellion since Labour came to power. The revolt on a technical motion was a disappointment for Mr Blair who had sought to unite his party by stressing his commitment to a United Nations solution to the Iraq crisis and distancing himself from President George Bush's demands for "regime change". The scale of the rebellion suggests he has not yet convinced his party on his support for Mr Bush's hardline stance.

Mr Blair said the "whole nature of the regime" would change if Iraq was disarmed and No 10 officials added that President Saddam could still "save himself" by getting rid of his weapons.

He also pledged to call a new peace conference on the Middle East, saying the international community should pursue that goal with the same vigour as it tackled President Saddam's weapons of mass destruction.

Mr Blair was warned by MPs from all parties that he would run into a storm of protest if the UN failed to resolve the crisis and he then supported unilateral military action by the United States.

In a statement at the start of the debate, Mr Blair said President Saddam's removal would be "wonderful", but stressed: "Our purpose is disarmament. No one wants military conflict."

He set out his case for action in the Government's long-awaited dossier on Iraq's weapons, published yesterday. It disclosed that Iraq had tried to obtain "significant quantities" of uranium from Africa and estimated that Iraq could produce a nuclear weapon in between one and two years if it secured fissile material and other components. The 50-page document, based on intelligence gathered by the security services, warned that some of Iraq's chemical weapons could be deployed just 45 minutes after an order was given to use them. "Despite sanctions and the policy of containment, Saddam has continued to make progress with his illicit weapons programme," the report said.

The report suggested the Iraqi leader did not regard his armoury as weapons of last resort but was ready to use them. It also outlined his efforts to develop long-range ballistic missiles capable of hitting Israel or British bases in Cyprus. The dossier appeared to raise doubts over the likely success of new inspections. It said Iraq was planning to conceal evidence of its weapons programme.

President Bush praised Mr Blair for "making the case" against President Saddam. The White House hopes that the document will help to persuade the UN Security Council to back a new resolution setting up a tough inspections regime, which may be tabled today. British officials welcomed signals that Russia and China were moving towards Britain's position. But the French President, Jacques Chirac, expressed opposition to threatening military action in the resolution.

Iraq branded the document "scaremongering, exaggeration and lies", and declared that UN inspectors would have unfettered access to establish the truth. A spokesman said: "Blair's evidence is a hotch-potch of half truths, lies, short-sighted and naive allegations which will not hold after even a brief investigation by competent and impartial experts."

Charles Kennedy, the Liberal Democrat leader, warned against a go-it-alone strategy by the US. "Those of us who have never subscribed to British unilateralism, we are not about to sign up to American unilateralism either," he said.

Although several Tory MPs expressed doubts, Iain Duncan Smith, the party leader, pledged strong support for Mr Blair.

The case against Iraq - key points of the dossier

The British Government dossier states that Iraq has:

* continued to produce chemical and biological agents;

* military plans for the use of chemical and biological weapons, including against its own Shia population. Some of these weapons are deployable within 45 minutes;

* developed mobile laboratories for military use, corroborating reports on mobile production of biological warfare agents;

* pursued illegal programmes to procure controlled materials of potential use in the production of chemical and biological weapons;

* tried covertly to acquire technology and materials that could enable the production of nuclear weapons in as little as one year;

* sought significant quantities of uranium from Africa, despite having no active civil nuclear power programme that could require it;

* recalled specialists to work on its nuclear programme;

* illegally retained up to 20 al-Hussein missiles, with a range of 650km, capable of carrying chemical or biological warheads;

* started deploying its al-Samoud liquid propellant missile, and has used the absence of weapons inspectors to work on extending its range to at least 200km, beyond the 150km limit imposed by the United Nations;

* constructed a new engine test stand for the development of missiles capable of reaching the UK Sovereign Base Areas in Cyprus and Nato members (Greece and Turkey), as well as all Gulf neighbours and Israel;

* learnt lessons from previous UN weapons inspections and has already begun to conceal sensitive equipment and documentation in advance of the return of inspectors.