An aide to the Iraqi prime minister said on Thursday that the government's Shi'te bloc rejected two demands by mostly Sunni lawmakers who want concessions in return for supporting a security pact with the United States. The dispute delayed a vote on the pact, which would allow US troops to stay in Iraq for three more years. The vote is scheduled for Thursday. Sami al-Askari, an aide to Prime Minister Nouri al-Maliki, said that Sunni lawmakers demand the repeal of a law designed to weed out senior members of Saddam Hussein's now-outlawed Baath Party from government agencies, and the dissolution of a special tribunal that was set up to try Saddam and top lieutenants.