Quebec's transport minister has left politics.

Jacques Daoust announced his resignation Friday afternoon, hours after Premier Philippe Couillard indicated the minister had lost his confidence.

Daoust, 68, had faced mounting criticism in recent months over his alleged role in authorizing the sale of a Quebec hardware chain to American giant Lowe's while he was the province's economy minister.

Although Daoust maintained he didn't know about Investissement Quebec's decision to sell its shares in Rona, emails sent in 2014 and obtained by TVA suggested the vice-president of the provincial investment agency had been given the go-ahead from Daoust's former chief of staff.

Members of the opposition had called for Daoust's resignation, accusing him of having lied to the public.

Couillard said Friday "serious questions" had been raised about the Rona sale and he wanted answers fast.

Daoust was appointed transport minister in January.

In a statement announcing his resignation, Daoust maintained he never knew about the Rona sale but didn't want to be a distraction to the government.