Progressive Conservative MLA Wes McLean announced on Monday he will not run for re-election in September. (CBC)

Some supporters of Progressive Conservative MLA Wes McLean are predicting a win for the Liberals in the northwestern riding now that their first-term MLA has decided to leave provincial politics.

McLean said on Monday he has decided to not seek a second term in the legislature and some of those who voted for him four years ago believe he's being pushed out by party insiders and say they won't support the Tories.

Robert Davenport, who lives outside Perth-Andover, calls McLean a "marvellous" MLA.

He is not a card-carrying Tory now but he planned to sign up as a Progressive Conservative to help McLean win the party nomination in Carleton-Victoria, a newly merged riding.

'Right at this present day, I would say the riding is going to go back to the Liberals.' - Robert Davenport

McLean has bowed out of the race and Davenport said he won't vote for the other Tory in the race, Dr. Colin Lockhart.

"If Lockhart takes the nomination, I won't be supporting him," Davenport said.

One reason behind Davenport’s decision not to support another Tory is that Lockhart is a doctor and Davenport said he believes that prevents him from being a full-time MLA, such as McLean.

"The few people that I know, and the family members I know, are of that opinion. They're not interested in having another doctor as an MLA," he said.

McLean defeated long-time Liberal MLA Larry Kennedy in 2010. Kennedy worked as a physician during his years in provincial politics.

McLean says he wasn’t pushed out

He said he also believes McLean has been forced out by party insiders who prefer Lockhart, a friend of Tory veteran Dale Graham.

McLean told CBC News on Monday that he wasn't pushed out of politics.

"There's been no move afoot for me to not run. I just made the conscious decision to not reoffer,” he said.

McLean said he will campaign for whoever wins the Progressive Conservative nomination in the new riding and he wants his supporters to do the same.

But Davenport said there are enough supporters of McLean who are so upset that their MLA is not running again that the Tories may not win the riding in September.

"Right at this present day, I would say the riding is going to go back to the Liberals," he said.

McLean is not the only Tory MLA who will not be running in September's election. The other Progressive Conservatives who have announced they won't seek re-election include: Jack Carr, John Betts, Dale Graham, Glen Tait and Greg Davis.

Liberal Roland Haché has also said he will not run in the upcoming election.