April 1 (Bloomberg) -- Prime Minister Gordon Brown shelved a plan to withdraw more British soldiers from Iraq after violence flared in Basra, where the U.K. has responsibility for security.

The U.K. will maintain a contingent of about 4,000 troops at the airbase outside the southern Iraqi city instead of reducing it to 2,500, as announced in October, Defense Secretary Des Browne said today in Parliament.

The withdrawal was derailed last week when Iraqi Prime Minister Nuri al-Maliki sent his army into Basra to crack down on Shiite militias, killing hundreds of people. That forced U.S. and British forces to provide air and artillery support.

``The conditions have changed and the military advice has changed,'' Browne said. ``It is prudent that we pause any further reductions.''

By backing away from the pullout, Brown is bowing to criticism made when his plans were announced Oct. 8. At the time, opposition lawmakers questioned the utility of keeping such a small British contingent in Iraq after sending 46,000 soldiers there at the time of the invasion five years ago.

Today the opposition Conservative Party accused the Labour government of seeking political gain by announcing the withdrawal last year.

``The government has been caught too often on the overoptimistic end of the spectrum,'' Conservative defense spokesman Liam Fox said. ``I hope that the government has now learned not to play party politics with projected numbers.''

Voters vs Allies

The decision gives priority to U.K. relations with President George W. Bush at the expense of appeasing voters at home who oppose the war. Brown announced plans to cut the force in Iraq as a way to distance himself from the Iraq war, which was one of the least popular initiatives of his predecessor, Tony Blair.

Last week's fighting between the government and the militias of Shiite Muslim cleric Moqtada al-Sadr erupted on March 25 in Basra before spreading to Baghdad. The violence forced the Iraqi government to impose a curfew there and the U.S. embassy to order staff to keep off the streets.

American aircraft joined the fray on March 27, striking suspected militia positions. A day later, Bush said the Iraqi government's decision to combat the militants marked a ``defining moment'' in the country's history.

Dead and Wounded

There are no official casualty figures for the battles. Agence France-Presse said more than 400 people died. Al-Sadr ordered his Mahdi Army fighters off the streets yesterday as the government eased curfews in the cities of Basra and Baghdad.

Ken Clarke, a former Conservative Cabinet minister who opposed the invasion in 2003, said even 4,000 troops may not be sufficient to ensure their own safety. The U.S. military has suffered 4,000 fatalities in Iraq and currently has 158,000 soldiers deployed there.

``A very violent military conflict broken out between two violent armies, and we are backing one of them,'' Clarke said in Parliament. ``Surely the purpose of having 4,000 people in Iraq now is to make sure they're in adequate numbers to safely withdraw, because they don't appear to be playing any useful part in the political development of the country.''

To contact the reporters on this story: Mark Deen in London at markdeen@bloomberg.net

Last Updated: April 1, 2008 12:14 EDT