Bob Rae has officially announced that he will not seek the permanent leadership of the Liberal party but will continue his role, in an interim capacity, until a new leader is chosen.
"The way in which I can serve my party best is by not running for the leadership," Rae told reporters Wednesday.
"It hasn't been an easy decision, but I think it's best for the party and it's a decision that I feel comfortable with."
The news is shocking, especially considering it came hours before the party executive was poised to formally release Rae from his pledge, as interim leader, not to seek the permanent helm.
According to CBC's Hannah Thibedeau, Rae had intended to run, up to as late as last week, but was "shocked at the push back" he was getting from people who felt he should honour his original commitment not to run.
"He was setting up a campaign team, getting ready for the leadership," she said.
Rae's decision opens the field considerably for other leadership contenders.
Liberal MP Justin Trudeau has been considered a favourite by many, but he has consistently maintained he doesn't intend to seek the role.
Earlier Wednesday, however, Trudeau revealed the pressure he was under to reconsider his decision not to seek the leadership was having an effect.
"Honestly I don't know," he told Toronto's 680News according to the Globe and Mail.
"I am continuing to say no but I won't lie to you, I'm under a lot of pressure to reconsider."
Other potential candidates considering their chances include MPs Marc Garneau, David McGuinty, Joyce Murray and Dominic LeBlanc.
The Liberals will choose a new leader in spring 2013.