MONTREAL - Conventional political wisdom holds that the island of Montreal is the exclusive domain of the federal Liberals and the Bloc Quebecois.

Other parties -- like the NDP with its lone seat in Outremont -- are really just interlopers, whose time and money are better spent elsewhere.

The Conservatives, though, have just made clear their intention to rewrite such hard-and-fast rules of Quebec politics.

Their new star candidate, Sen. Larry Smith, will not only seek election on the island but will be gunning for Lac-Saint-Louis, arguably one of the staunchest Liberal strongholds in the country.

The Liberal margin of victory over the Tories was 52 percentage points in 2004, 21 in 2006 and 22 in 2008.

The Conservatives are hoping Smith can provide a beachhead on the island that will herald a larger blue invasion, the likes of which hasn't been seen in these parts since Brian Mulroney was prime minister.

It is a tall order for Smith, a political novice with more experience in boardrooms than the nitty-gritty of local electioneering.

But the West Island, and Lac-Saint-Louis in particular, have many of the attributes that appeal to Conservative strategists.

It is a suburban area, largely anglophone, that has seen an influx of new Canadians in recent years.

In that respect it resembles some of the ridings in the 905 area code around Toronto, where the Conservatives managed an upset win in a byelection last month in the Liberal fortress of Vaughan.

Taken together it may mean the Liberal incumbent in Lac-Saint-Louis, Francis Scarpaleggia, is facing his toughest campaign yet.

But Scarpaleggia, who has represented the riding since 2004, claims his preparation will be no different against Smith than it was for his other opponents.

He nevertheless wasted little time trying to take the sheen off the former CFL star.

"The fact he's running here is a sign to me it's a Hail-Mary pass," Scarpaleggia told The Canadian Press on Wednesday.

"I live in my riding, I live in my community, Larry Smith doesn't. His candidacy did not come from the community."

Smith lives in nearby Hudson, which is located in a riding where a Bloc Quebecois MP has recently brought down big-name candidates, Liberal and Tory alike.

Scarpaleggia suggested West Island voters wouldn't take kindly to Smith being appointed to the Senate on a Monday and then announcing his political ambitions the following day.

"Stephen Harper is using the Senate as a plaything for his ambitions," Scarpaleggia said.

The Liberals are hoping to characterize the showdown in Lac-Saint-Louis as a fight between Smith, the glossy outsider, and their hard-working but little-known MP.

Beyond this clash of personalities, though, Liberal organizers are confident recent demographics play in their favour.

Smith's supporters are fond of pointing out to skeptics that during the Mulroney years, the area was held by the Progressive Conservatives.

If it voted blue once, goes their reasoning, there is no reason it can't do so again.

Liberals counter that Lac-Saint-Louis's precursor, Lachine-Lac-Saint-Louis, had vastly different boundaries.

They say the bulk of PC votes at the time came from Lachine, which is no longer part of the riding.

"For people here, it's not about the Liberal brand per se," Scarpaleggia said. "They simply embrace traditional liberal values."

Gerry Weiner, a cabinet minister in Mulroney's government and a one-time West Island mayor, believes real momentum is building for Smith and other Conservative candidates on the West Island.

"In the past year, several ministers have come through to help build campaign teams," he said.