On December 23rd, Grand Ayatollah Ali Sistani rejected a US backed plan for a new coalition in the Iraqi parliament that would have allied the Shiite Supreme Council for Islamic Revolution in Iraq (SCIRI) with the Sunni Arab Iraqi Islamic Party and the Kurdistan Alliance. The plan aimed at isolating the 32 Sadrist members of parliament and depriving them of the ability to bring down the prime minister. Sistani rejected the plan on the grounds that it would split the Shiite majority. Sistani is insistent that the Shia majoritarian position be recognized and they receive the consequent power and influence. More

On December 25th, British troops raided the headquarters of an Iraqi police unit in Basra, claiming they heard that the unit was infiltrated by Shiite militiamen and planning to kill their prisoners. Basra City Council withdrew co-operation from UK forces in southern Iraq to protest the raid. Local officials said they had not been informed of the operation and it violated earlier agreements to move the prisoners without military action.
Blog Entry From Juan Cole

The US military has also conducted raids against the Badr Corps militia of the Shiite Supreme Council for Islamic Revolution in Iraq, in the course of which it arrested four Iranian officials. It had to let two of them go when it transpired that they were diplomats invited into Iraq by President Jalal Talabani, a close US ally. Juan Cole writes that "SCIRI and Badr were in exile in Iran for over two decades and have close ties to the Iranian regime. Nevertheless, the Bush administration hosted SCIRI leader Abdul Aziz al-Hakim recently The US military has for the most part characterized the Badr corps as disciplined and not the main security problem in Iraq. US troops have never had an engagement with Badr. The Badr Corps has been accused of infiltrating the special police commandos of the Interior Ministry and of using that unit to engage in ethnic cleansing of Sunni Arabs they suspected of membership in the guerrilla movement. That Badr had close ties to Iran was well known, so it is a little unclear what new developments could have provoked this raid.". Iran protests US arrests in Iraq