The federal Liberals continue to score higher than the other political parties on the Nanos Party Power Index but their advantage has diminished over the past four weeks. Four weeks ago they enjoyed an 11 point advantage but that advantage has dropped to six points.

The federal Liberals received a score of 58 points out of 100, followed by the Conservatives at 52 points, the NDP at 50 points, the Green Party at 32 points and the BQ at 26 points (in Quebec only).

Readers should note that the weekly data was collected before the shooting incident in Ottawa.

The five point advantage enjoyed by Liberal Leader Justin Trudeau over Conservative Leader Stephen Harper remains unchanged in the current wave of tracking.

Thirty four per cent of Canadians preferred Trudeau as prime minister followed by Harper at 29 per cent, NDP Leader Thomas Mulcair at 19 per cent. And Green Leader Elizabeth May at five per cent (12 per cent of Canadians were unsure).

The Liberals still have the highest pool of accessible voters but there has been a noticeable one week four point slide on this measure that should be monitored.

Asked a series of independent questions, 54 per cent of Canadians would consider voting for the Liberals, 43 per cent would consider voting NDP, 41 per cent would consider voting Conservative and 28 per cent of Canadians would consider voting for the Green Party.