British troops stationed near Basra are at risk of being drawn into fighting with Shia militiamen. The Foreign Secretary, David Miliband, who is on a visit to Baghdad, has offered support to the Iraqi government's offensive against the Mehdi Army.
Britain has 4,000 soldiers at Basra airport and has delayed pulling out 1,500 of them because of the fighting in late March between Iraqi government forces and the supporters of the nationalist cleric Muqtada al-Sadr. "Over the past few weeks, the government... has taken decisive steps to extend security in key parts of the country," said Mr Miliband. He later had private talks with the Iraqi Prime Minister Nouri al-Maliki, who stressed his determination to crush the militias, though in truth he is only targeting the Mehdi Army and not the militias of parties that support him.
Mr Maliki's military attack, which started on 25 March, failed to make any gains until it was backed by US troops, advisers, helicopters and fixed wing aircraft in Basra and Baghdad.
In Basra, British forces provided advisers and artillery support.
Des Browne, the Defence Secretary, told MPs last month that the departure of the 1,500 troops was being delayed because of the upsurge in violence, pending a review. But yesterday he made it clear in an update to MPs that the troops will remain indefinitely and he set no date for their return to Britain.
Mr Browne said: "It remains our clear direction of travel and our plan to reduce our force levels as and when conditions allow. But while the situation on the ground continues to evolve rapidly and while military commanders continue to assess the changing environment in Basra, it remains prudent that we take time to fully consider further reductions."
A former Labour defence minister, Peter Kilfoyle, said: "I think this is a big mistake. I still maintain there is no practical reason why our troops are not being brought home, given they brought American troops down to Basra. The British troops are being used as political cover for America."
Mr Maliki's crackdown on the Mehdi Army has already led to the US army sealing off Sadr City, the Sadrist stronghold in east Baghdad. Five people were killed and 28 wounded in Sadr City early yesterday and another eight were killed and two wounded in the Shia district of Husseiniyah north of Sadr City.
Given that Iraqi army units have regularly retreated without orders or defected, it is doubtful if Mr Maliki's forces can hold their own without US backing.
Mr Sadr has demanded an immediate withdrawal of all US troops from Iraq and threatened over the weekend to wage "open war" if Mr Maliki does not call off his campaign. So far, the Sadrists have tried to avoid an all-out military confrontation with their Shia rivals. "For us, this government has lost its credibility as a government of national unity," said a Sadrist member of parliament Ahmed al-Masoudi.
"It does not represent all the sects of Iraq and we are not ready to join a government which is a threat to the new Iraq."
Mr Maliki is threatening to stop the Sadrists taking part in the provincial elections in October in which they are expected to do well.
"It is forbidden to practise peaceful political activity while carrying arms," he said. "Everyone should work as politicians and it is not permitted for a single weapon to be outside the hands of the state."
Mr Maliki's political position is strong because he is being backed by the Americans and the Kurds, both of whom have wanted to get rid of him at different times in the past 18 months.
He is also likely to be reinforced by the Sunni Arab bloc, the Accordance Front, that walked out of his government last year. It will soon submit a list of candidates to become ministers.