Queensland state Labor MP Ronan Lee says he has defected to the Greens because the Government has ignored his concerns about the environment.

Mr Lee says he had a tense conversation with the Premier Anna Bligh today when he told her he was resigning from the ALP to join the Greens.

"The message I gave to her on the phone today was you've got to green up your government," he said.

Mr Lee will give up a position as a parliamentary secretary to become the first Greens MP in the Queensland Parliament.

His opposition to Labor policies like building the proposed Traveston Crossing Dam near Gympie was behind his decision to jump ship from the Government.

"We can do much better than that here in Queensland," he said.

"I think that my future as someone who wants to make positive change for my community and on the environment is with a wonderful party like the Queensland Greens."

Ms Bligh says one MP's defection does not mean her Government is in crisis.

"We are a strong Government with a strong majority and we are going to get on with the business of governing Queensland," she said.

She says the people who got Mr Lee elected have a right to feel betrayed.