Liberal Leader Stephane Dion has suddenly booked a Sunday event in Toronto in the wake of some new polls that show the NDP to be hot on his heels in cities.

"In the 416 and cities around the country, there are signs of Liberal vote erosion to the point where the NDP vote is surging," CTV's Graham Richardson told Newsnet on Saturday from St. Catharines, Ont.

The Dion campaign has taken Sundays off so far this campaign, but after flying to Ottawa tonight, Dion and his wife Janine Krieber will fly to Toronto on Sunday for an event with Liberal women.

Toronto has been Liberal bedrock since 1993. The party holds 20 of 23 seats in Canada's largest city, with the NDP holding three. The Conservatives were shut out in 2006.

Richardson said the move to hold a previously unscheduled event on what should be safe ground could be seen as a sign of panic by the Dion camp.

Dion -- campaigning in Hamilton and St. Catharines on Saturday after a rally in London on Friday -- was in Toronto earlier this past week and did not hold a large rally there, he said.

The question that arises out of this is "if there's Liberal slippage in Toronto ... if this is seen as a contest between (NDP Leader) Jack Layton and (Conservative Leader) Stephen Harper, the Liberal leader risks being seen as a third-place finisher," Richardson said.

"These things can take on a life of their own. People can get to the point where people aren't listening to Mr. Dion," he said.

And if the Liberal vote does collapse, the big question becomes one of where it goes, Richardson said.

However, pollster Peter Donolo of The Strategic Counsel told Newsnet that the concentration of the Liberal vote, compared to the diffuse nature of NDP support, means the Liberals are unlikely to be dislodged as the official opposition.

But it's also unlikely the Liberals will overtake the Harper Conservatives at this point. "It's about whether they can hold Mr. Harper back to a minority situation and hold as many seats as possible for themselves," he said.

Layton, Harper

Layton, the MP for Toronto-Danforth, held a major rally in Vancouver on Saturday. "Here in B.C., the choice is clear -- if you want to stop Harper,  only New Democrats can do it," he said.

Layton is scheduled to be in Toronto on Sunday to release his party's platform.

Harper spoke Saturday at a Conservative rally in Ajax east of Toronto, where he mainly attacked Dion and ignored Layton as he tried to seek support for his party in the GTA.

He particularly took aim at Dion's proposed Green Shift -- which he described as a carbon tax without mentioning the accompanying income tax cuts -- and claimed a Liberal government would plunge the country into deficit.

"The GTA doesn't need higher taxes, the GTA does not need a carbon tax, and the GTA does not want this country to go back into deficit," he said.

Dion unveiled his party's platform this past week and insisted a Liberal government would not run a deficit.

Harper touted his party's get-tough-on-crime approach and management of the economy. He also listed some GTA spending:

• A new passport office in Ajax
• A bridge in Pickering
• Federal gas tax transfers that will direct $800 million to the GTA by 2010
• Transportation investments

Harper described his government -- while imperfect -- as proven and prudent, with the Greens, NDP and Liberals a risk.