At least 475 of 500 MPs are required to convene the first meeting of the House of Representatives. The EC has endorsed 358 MPs.

EC secretary-general Suthipol Thaweechaiyagarn said the agency would investigate complaints against the remaining winners, and endorse the results if it finds no reason to pursue the complaints.

Pheu Thai's potential prime minister Yingluck Shinawatra and outgoing Prime Minister Abhisit Vejjajiva are among those still waiting.

He said the EC expects to announce the suspension of winning candidates, if any, on July 19 and new elections will take place on July 31.

Mr. Suthipol said a subcommittee has been set up to consider the qualifications of eight party-list and four constituency winners from Pheu Thai who have been charged in connection with political violence.

The panel has seven days to complete its task and report the finding to the EC, he said. Ms. Yingluck and Mr Abhisit yesterday expressed confidence that they could clarify themselves and receive endorsement from the EC.

Ms. Yingluck said she had no idea what complaints she faced but said that she can clarify any queries. "Let the election officials say what it is about. I think I have followed the rules." The Democrats' Mr. Abhisit said he is not worried about the delay in endorsement and is adamant he has not broken any law.

On the red shirts' plan to pressure the EC to endorse Pheu Thai winners, he said the pressure must stop and the agency should be allowed to do its job.

Pheu Thai successful candidate Pirapan Palusuk yesterday questioned the EC's decision not to endorse some party list winners.

Mr. Pirapan said the EC either endorses the entire party list, or doesn't endorse it. He said if any individual candidates are suspected of violating poll regulations, legal action should be taken against them.

"Not endorsing some list candidates can't be right. This is because voters vote for the party, not individuals," he said.