Manitoba Liberals are stunned to learn one of their own may be running as a Conservative in the federal election.

Winnipeg School Trustee and longtime Liberal Joyce Bateman is expected to announce on Friday that she will run as the Conservative candidate in Winnipeg South Centre — against another longtime Liberal, MP Anita Neville.

Dougald Lamont, who volunteers for the party and always considered Bateman a staunch Liberal, says many in the party feel betrayed.

It was Liberals who helped Bateman get elected trustee in the October 2010 municipal election.

"I think she's making a terrible mistake. She's burning the bridges of all the people that supported her," he said.

He can't figure out why she would suddenly change to a party that represents a whole different philosophy.

"I don't understand how someone who has been a liberal their whole life would say this is a party I need to run for."

Bateman could not be reached for comment.