After weeks of rumours, Vancouver city councilor Peter Ladner has finally decided to wage war against an old friend.

The councilor officially announced his intention to seek the mayor's chair -- currently held by his own party's Sam Sullivan -- Thursday morning.

"I'm not here to bash the mayor," Ladner told reporters. "I'm here to offer an alternative.

"When I am on a team and I see the ship heading towards the rocks I feel an obligation to change course and offer an alternative," he said.

Ladner has spent six years in civic politics. He was first elected during Larry Campbell's successful mayoral election campaign.

Vision Vancouver Councillor Raymond Louie and Parks Board Commissioner Allan De Genova have also expressed an interest in the city's top job.

Mayor Sullivan wasn't available today, but told CTV News last week that he wasn't finished in his job as the mayor.

"It's a wonderful job that I have and I'm sure lots and lots of people would want it," he said last week.

Three years ago, the former deputy premier, Christy Clark, wanted the job. She was approached to take a run at the NPA leadership and was considered a shoe-in.

But Sullivan beat her.

"He's tough, he's tough," said Clark in an interview Thursday. "I certainly saw how tough he can be when I ran against him. No holds barred, nothing for Sam gets in the way of winning."

Clark became a talk radio host, and her guest Thursday was Peter Ladner. The irony was not lost on both of them.

Ladner now has to convince the board of his party, the Non-Partisan Association, that it should hold an open nomination meeting, and not simply endorse the incumbent Sullivan.

The party is conducting polls to gauge the mood of the voters, clearly not wanting to back a losing candidate.

With a report from CTV British Columbia's Janet Dirks