The timing of the announcement could be intended to take pressure off Tony Blair as he faces a difficult week over Labour opposition to his reform agenda and a mass protest in London at the weekend in favour of pulling troops out.
Mr Blair was urged last week by families of the 103 British soldiers killed so far in Iraq to withdraw the troops, and the calls intensified as Iraq appeared to be on the verge of civil war. The Defence Secretary said civil war was "neither imminent nor inevitable" but he avoided ruling it out.
Reg Keys, whose son Tom was one of six military policekilled in an incident in 2003, said: "I hope this means ministers have begun to see the light and accepted the need for a phased withdrawal."
Mr Keys, who stood against Mr Blair in his Sedgefield constituency at the last election to protest against the war, said: "Iraq has been a catastrophic political mistake and a strategic failure. The key tipping point was when we saw those tanks and soldiers in Basra being burned.
"The honeymoon period for our troops over there is well and truly over. British forces were never going to be accepted from that point on. It is just going to be a constant trickle of flag-draped coffins until the Government starts a phased withdrawal."
Labour MPs warned that the troops are seen as an occupying force, and are part of the problem rather than the solution. The cut in numbers deployed in the Basra area raised hopes that Britain and the United States are planning to make large-scale reductions later in the year. A review is being launched in April by the Iraqi authorities, which could lead to more forces being brought home.
The Defence Secretary said the reduction amounted to 10 per cent of the total British force, and would cut the deployment from 8,000 to 7,200. They were being pulled out because their duties, training Iraqi forces and protecting military installations, were done. He stressed that it was not being brought about because more security tasks were being handed over to Iraqi forces. That could come later in the year.
"We're not handing over large territories of Iraq. That is something we will be looking at," the Defence Secretary said. "It is a significant step on the way but it is not yet the full hand-over to the Iraqis."
The 7th Armoured Brigade will be replaced in early May by the 20th. Units on standby to relieve troops already deployed there include the 1st Queen's Dragoon Guards, the Queen's Royal Hussars, 12th Regiment Royal Artillery, 1st Battalion Grenadier Guards, and 1st Battalion The Princess of Wales' Royal Regiment. Reserves to be sent out include the Lancastrian and Cumbrian Volunteers and the King's and Cheshire Regiment.Reuse content