With less than a week to go before voting day, a new poll suggests the Ontario Liberals and Progressive Conservatives are in a very tight race.

The Nanos Research poll for CTV, CP24 and the Globe and Mail puts the Liberals at 37.7 per cent support, the Tories at 33.4 per cent and the NDP at 25.5 per cent. According to the survey, which included responses from 529 decided voters, the Green Party is way back at 2 per cent support.

While on the surface, the new numbers suggest the Liberals have a slight edge, the two front-runners are within the margin of error of each other. The poll's margin of error is +/- 4.3 per cent.

The support for each party has remained steady since the last Nanos poll on party support, which was released on Sept. 12. Those results put Liberal support at 38.1 per cent, Tory support at 34.7 per cent and the NDP at 24.3 per cent. The Greens had 2.7 per cent support.

The latest data suggests that Tuesday night's leaders' debate "has not provided any breakaway momentum for any of the two front runners," pollster Nik Nanos told CTVNews.ca.

As the candidates head into the home stretch ahead of the Oct. 6 vote, Nanos said the key is for each to "avoid making a mistake."

"Mistakes in the close of the campaign can be lethal to a campaign," Nanos said. "We are now likely shifting to the ground war where organization and local preparedness are important."

The poll also asked respondents to say which leader, if any, won the leaders' debate.

Of the 600 respondents, 39.5 per cent said they were undecided about who won, while 25.4 per cent said there was no overall winner.

Of those who chose a leader as winner, 14 per cent selected Liberal Leader Dalton McGuinty, 11.5 per cent said NDP Leader Andrea Horwath and 9.5 per cent picked Progressive Conservative Leader Tim Hudak.

For that part of the poll, the margin of error is +/- 4 per cent.

Nanos noted that the debate figures show that while no clear winner emerged, Horwath left a positive impression on viewers. However, that "did not convert into the perception that she won, or a surge in support," he said.