A poll suggests the federal Conservatives have maintained their small lead over the Liberals, while support for both parties increased slightly over the past two weeks at the apparent expense of the NDP.

According to the latest results from EKOS, released exclusively to CBC News, 33.1 per cent of respondents said they would vote for the Tories if an election were held today, compared with 29.9 per cent for the Liberals.

The New Democrats received 13.3 per cent support, down more than three percentage points from two weeks ago, according to EKOS.

The poll results come after NDP Leader Jack Layton faced heavy criticism for allowing his MPs a free vote on a Conservative backbencher's bill to repeal the federal long-gun registry.

In the end, enough New Democrat MPs voted along with their leader to scrap Tory MP Candice Hoeppner's private member's bill and preserve the registry, although Layton has proposed legislation to address rural and aboriginal Canadians' concerns with the registry.

Meanwhile, support for the Green Party remained roughly the same at 10.9 per cent, while support for the Bloc Québécois rose slightly to 10.1 per cent, the EKOS poll suggests.

In Ontario, the Conservatives and Liberals are once again deadlocked in a chronic "see-saw battle" that will likely determine the outcome of the next election, according to the pollster.

The random survey of 2,267 Canadians aged 18 and over was conducted Sept. 22-28 and carries a margin of error of plus or minus 2.1 percentage points, 19 times out of 20.

Coalition support gauged

In a separate EKOS survey, respondents were also asked whether they would prefer a Conservative government led by Stephen Harper or a coalition government made up of Liberals and New Democrats and led by Liberal Leader Michael Ignatieff.

Forty-one per cent of respondents said they would prefer an Ignatieff-led coalition, while 39 per cent said they preferred a Harper-led Conservative government.

EKOS also asked respondents their preferred outcome for the next federal election, giving them four options: a majority Conservative government, a minority Conservative government, a majority Liberal government or a minority government.

Twenty-six per cent said they wanted a majority Conservative government, while 22 per cent said they preferred a Liberal majority government.

The poll posed the questions to a random sample of 3,782 Canadians aged 18 and over between Sept. 16 and Sept. 28. It carries a margin of error of plus or minus 1.6 percentage points, 19 times out of 20.