By Panarat Thepgumpanat

BANGKOK Thailand's poll body will refer to the Constitutional Court a case over whether prime ministerial candidate Pita Limjaroenrat should be disqualified as a lawmaker over a shareholding issue, local media and an election commission source said on Wednesday.

The referral of the case was reported by three media outlets. A source from the commission told Reuters it would request that Pita, the leader of the election-winning Move Forward Party, be suspended as a parliamentarian pending the court's ruling.

The source declined to be identified because they were not authorised to speak to media.

The referral comes a day before Pita is due to contest a vote of on the premiership in the bicameral parliament. He has the backing of eight parties in an alliance seeking to form the next government.

The progressive Move Forward and another opposition party, Pheu Thai, trounced rivals allied with the army in the May 14 election, in what was widely seen as an overwhelming rejection of nine years of government led or backed by the military.

The poll body was investigating a complaint alleging Pita's ownership of shares in media firm iTV at the time of his registration made him ineligible to stand in the May 14 election.

Pita has maintained iTV has not been an active mass media organisation for many years.

Move Forward in a statement accused the election commission of rushing its referral of the case and said Pita should have been given a chance to respond and refute the allegations.

(Reporting by Panarat Thepgumpanat and Panu Wongcha-um; Writing by Martin Petty; Editing by Kanupriya Kapoor)