MNA Jean D'Amour says he will sit as an independent pending the outcome of investigations by provincial police and the province's chief electoral officer. (CBC)

Liberal MNA Jean D’Amour says he will temporarily sit as an independent in the national assembly pending the results of an investigation into his involvement in municipal politics.

In a news conference Tuesday at the national assembly, the former mayor of Rivère-du-Loup acknowledged having received an envelope containing $500 cash during the campaign to elect his successor in 2007.

D’Amour said an entrepreneur had left the money at his house, with a note saying it was to help candidate Michel Morin with his campaign.

D’Amour said he advised Morin about the situation because he was concerned it could be illegal campaign financing.

He said Morin told him to refuse such donations.

D'Amour said he returned the money to the un-named entrepreneur. Morin went on to win the election.

D’Amour, who is already under investigation by the province’s lobbying commissioner, said he has advised provincial police of the situation and has written to the province's chief electoral officer.

The MNA said he is coming forward now because of recent media reports and did not contact police earlier because he was confident the entrepreneur in question gave him the money out of ignorance of the province's electoral laws.

"My integrity does not have a price," said D'Amour.

He says he intends to return to the Liberal caucus once his name has been cleared.

The opposition Parti Quebecois used D'Amour's situation to call once again for a public inquiry into allegations of collusion and corruption involving politicians and members of the construction industry.

Last month the government announced it was creating a special squad known as Operation Marteau, French for Operation Hammer, to investigate allegations of corruption and collusion involving the construction industry.