Matt Birney retires from politics

Former state opposition leader Matt Birney has officially retired from politics, saying that the instability of the Liberal Party's leadership has made it difficult for the party to win the election.

The announcement from Mr Birney comes as the Liberal Party finalised its candidates for the September 6 election.

Mr Birney, the member for Kalgoorlie, told ABC he had rejected an offer to run for the seat of Alfred Cove.

Earlier this year, Mr Birney accepted a non-executive chairman role at Subiaco-based Carbon Conscious Ltd.

The company plans to produce carbon credits through the planting of mallee eucalypt trees throughout the Wheatbelt.