MANILA, Philippines -- The Senate and the House of Representatives has decided to postpone until Wednesday the holding of a joint session to tackle the martial law imposed in Maguindanao by President Gloria Macapagal Arroyo.

The joint session of Congress was supposed to be held on Tuesday.

Senate Majority Leader Juan Miguel Zubiri said Monday night that the two chambers could only convene on Wednesday because they have not finalized the ground rules for the joint voting.

Zubiri and a group of senators met with their House counterparts Monday night to come up with rules on how Congress would go about its joint voting on the proclamation.

Congress is required to look into any proclamation of martial law by the President.

President Arroyo imposed martial law in Maguindanao allegedly to quell a rebellion by armed supporters and followers of the Ampatuans, who are accused of being behind the Nov. 23 massacre of local politicians, supporters and journalists in Ampatuan town.