Prospective voters in this fall's Ontario election have mixed views on who is the most trustworthy leader, but new poll results put Premier Dalton McGuinty slightly ahead of Conservative Leader Tim Hudak.

Nanos Research polled 1,000 voting-age Ontarians on behalf of CTV, CP24 and The Globe and Mail and asked them which leader they considered the most trustworthy.

Twenty-eight per cent of respondents picked McGuinty, while 23 per cent said they trusted Hudak the most.

Ontario NDP Leader Andrea Horwath netted 14 per cent support from those who took part in the survey, while three per cent chose Ontario Green Leader Mike Schreiner.

Fourteen per cent said they were undecided, while 19 per cent said that none of the leadership candidates were notably trustworthy.

Nanos also asked Ontarians which provincial leader had the best vision for the province's future, a category in which the premier also bested his opponents.

Twenty-nine per cent of respondents said McGuinty had the best vision, putting him slightly ahead of Hudak (26 per cent), as well as Horwath (13 per cent) and Schreiner (3 per cent).

Seventeen per cent of surveyed voters were undecided about the vision question, while 13 per cent said that none of the leaders had the best vision.

Nanos conducted the research for both of its polls between August 10 and August 13.

Each poll is considered accurate to within 3.1 percentage points, 19 times out of 20.

McGuinty has led the Ontario Liberals for the past 15 years and was first elected to the provincial legislature in 1990. He became premier when the Liberals won a majority government in 2003.

Hudak was first elected as a Progressive Conservative MPP in June 1995. He later served as a provincial cabinet minister in the Mike Harris and Ernie Eves governments and became leader of the Ontario PC party two years ago.

Horwath won a seat in the provincial legislature during a 2004 byelection. She became leader of the Ontario New Democrats in March 2009.

Mike Schreiner has led the Green Party of Ontario since November 2009. The Green party does not have any elected members in the legislature.

Changing voting patterns?

As Ontarians prepare to elect a new premier, about 20 per cent of voters are looking to change allegiances and vote for a new party in the October election.

The Nanos Research poll suggests that swing votes could have a large impact on the final outcome.

"Almost 1 in 5 are looking to vote for a different party in the coming provincial election," said pollster Nik Nanos in a news release.

With the Progressive Conservatives and the Liberals running closely in the polls, it isn't clear which parties would most benefit from new supporters.

The respondents were asked how likely they were to "vote for a party provincially that you voted for in the recent federal election."

Polling data released Sunday evening suggests that Tim Hudak's Progressive Conservatives have support of 42.1 per cent of voters. By contrast, the incumbent Liberals have moved up slightly to 37.6 per cent support.

Along with indications that voters could switch parties before the October vote, polling also suggests that some residents in the province are experiencing voter fatigue.

In the last year, Ontarians have also cast ballots federally, and in municipal elections.

When asked how they viewed the third election in a year, 52.4 per cent said it was a time to renew interest in politics, while 40.9 per cent said that the provincial vote was simply a "necessary nuisance."

According to Nanos, the numbers correspond with the last provincial vote in 2007, when 53.6 per cent of eligible voters cast ballots.

"One might conclude that many of those who stated that they see the election as a ‘necessary nuisance' will not necessarily vote," Nanos said.

"It suggests that there is some election fatigue as voters prepare to vote for a third time in one year."