The call was made on Sunday by Pheu Thai spokesman Prompong Nopparit.
If the EC did not take action against the PDRC, Pheu Thai would sue it for neglect of duty. The EC must be held responsible for the 3.8 billion baht spent on the Feb 2 election only to see it nullified, he said.
Mr Prompong hoped the EC would not let a political vacuum happen in the country and take the necessary steps to hold a new election as soon as possible.
He also called on Abhisit Vejjajiva to resign as Democrat Party leader to make way for democracy-loving people to lead the party. Mr Abhisit should not stay on in the position in the hope of being made prime minister under Section 7 of the constitution, he added.
On Mr Suthep's plan to hold a major rally on Mar 29 to demand the government's ouster, Mr Prompong called for people throughout the country to wear black to show symbolic opposition to the PDRC.