Sources say Premier Kathleen Wynne will be announcing a mini cabinet shuffle this morning, triggered by the departure of her environment minister to the Pembina Institute.
Environment Minister Glen Murray is leaving his cabinet position and will resign his Toronto Centre seat on Sept. 1.
The announcement comes as a surprise, as Murray had previously indicated he would run again in next year's election.
Murray will become the executive director of the Pembina Institute, an environmental think-tank.
Murray says in a statement that he is leaving Ontario politics to fight climate change at the national level.
Murray has been a fierce defender of his environmental positions and under his tenure the ministry implemented an ambitious cap-and-trade program aimed at reducing greenhouse gas emissions.