Rocco Rossi has announced he's bowing out of the race to succeed David Miller as the next mayor of Toronto.

After calling a last-minute press conference at his campaign headquarters, Rossi said shortly after 9 p.m. that he would be exiting the race effective immediately.

Rossi's withdrawal came hours after a new poll showed that his support had dropped from six per cent to four per cent of decided voters.

Newstalk 1010 host John Tory announced the results of the new Ipsos-Reid poll. They indicated that George Smitherman has 31 per cent support compared to 30 per cent for Rob Ford.

That represents a gain of eight percentage points for Smitherman since the last Ipsos-Reid poll, while Ford is up two points.

"Under the current scenario, it has become clear that my message is not what the majority of Torontonians want to focus their attention on," Rossi said.

"Accordingly, and respecting the obvious new mood of the electorate to see this two-way battle unfold, I'm announcing tonight that I'm withdrawing from the mayor's race effective immediately.

"I don't want to distract from Torontonians taking a very close look at the frontrunners, asking the tough questions and demanding tough solutions for Toronto," he said, adding that he would not be endorsing any candidate.

In a statement released minutes afterwards, Smitherman praised Rossi for "what was surely a difficult decision."

"Since early January, I have watched Mr. Rossi in action and I have been consistently impressed by his bold thinking, his wit and his passion for building a better, more inclusive Toronto," Smitherman said. "I wish Mr. Rossi and his family well, and every success in whatever he chooses to do next."

Earlier this week, a number of former Rocco Rossi campaign workers threw their support to Smitherman. But Rossi played down the move, saying they weren't important members of his team.

Smitherman's biggest prize was Rossi's former campaign manager, Sachin Aggarwal, who was replaced by Bernie Morton in late August.

"Over the next two weeks, voters will have to decide what kind of Toronto they want, who can best represent their values and who can get Toronto working again," Aggarwal said of the move. "It is clear from this move that George is the only candidate who can stop Rob Ford."

"I have great respect and admiration for Rocco, but we need to put our emotions and friendships aside, and unite behind a common banner to save our city."

Joe Pantalone is running in third with the support of 11 per cent of decided voters, according to the latest poll.

Sarah Thomson exited the mayoral race in late September and endorsed Smitherman.