SINGAPORE, Jan 15 (Reuters) - Singapore Prime Minister Lawrence Wong stripped Pritam Singh of his post as Leader of the Opposition on Thursday, saying his position had become untenable after his conviction for lying to parliament.

The move, the first of it's kind in Singapore, comes after parliament decided in a vote that Singh of the opposition Workers' Party was unsuitable to continue in the post given his "dishonourable and unbecoming" conduct after a lying conviction.

Wong in a statement said this decision was necessary to uphold the rule of law, as well as the dignity and integrity of parliament.

"Having considered the matter carefully, I have decided that Mr. Singh’s criminal convictions, taken together with Parliament’s considered view of his unsuitability, make it no longer tenable for him to continue... Mr. Singh’s designation as the LO will therefore cease with immediate effect," Wong said.

The Leader of the Opposition is designated by the head of government and not provided for in the constitution or parliament's standing orders.

Singh will remain a lawmaker. The Workers' Party said it would study Wong's statement.

"We will deliberate on its contents carefully through our internal processes and respond in due course," it said.

(Reporting by Xinghui Kok and Jun Yuang Yong; Editing by Martin Petty)