BANGKOK, July 12 (AFP) - Thailand's Election Commission recommended Wednesday that the Constitutional Court suspend prime minister frontrunner Pita Limjaroenrat over allegations he broke campaign rules as an MP, just a day before a parliamentary vote for the premiership.

Pita's progressive Move Forward Party (MFP) won the most seats at May's election, as voters delivered a crushing rejection of the army-linked parties that ran the kingdom for nearly a decade.

But he has faced a number of challenges, and last month the Election Commission (EC) set up a special committee to investigate whether he was qualified to run for office.

"The EC will send a case to the Constitutional Court for ruling," a commission statement said Wednesday.

Chairman Ittiporn Boonprakong confirmed to AFP the body had recommended the court suspend Pita as an MP.

It is unclear when the Constitutional Court may rule, should it accept the case, although the body is due to meet Wednesday.

But the decision will cast yet more uncertainty over parliament's vote for prime minister on Thursday.

Under Thailand's rules, even if Pita is suspended as an MP, he is still eligible to run for prime minister.