OTTAWA -- New polling suggests Liberal and New Democrat voters think Jean Charest or Patrick Brown would make the best leader of the federal Conservative party.

The data released by the research firm Leger is based on an online survey it did of 1,528 Canadian adults last weekend using computer-assisted web interviewing technology.

It cannot be assigned a margin of error because internet-based polls are not considered random samples.

The survey asked respondents which of the six candidates in the running they believe would make the best leader of the party, which will unveil its new leader Sept. 10.

Leger executive vice-president Christian Bourque says one of the issues they come across when they poll Canadians about a party leadership race is that roughly one-third appear indifferent.

The data suggests 58 per cent of respondents answered they didn't know or picked none of the above when questioned on which candidate would make the best Conservative leader.

When it came to Conservative voters, the polling suggests 23 per cent of respondents said they didn't know and only eight per cent selected none of the above.

Of Tory voters who responded to the survey, data suggests 44 per cent of them believe Pierre Poilievre, the longtime Ottawa-area MP known for his attacks on the government and Bank of Canada over inflation, would make the best party leader.

Charest, Quebec's former premier, came in a distant second at 14 per cent among Conservative voters, according to the survey's findings, while the four other remaining candidates ranked much lower.

Looking at respondents who back other political parties, Leger's data suggests 25 per cent of both federal Liberal and NDP voters feel Charest would make the best Conservative leader.

It also suggests 11 per cent of both Liberal and NDP would select Brown, who is mayor of Brampton, Ont., and formerly led Ontario's Progressive Conservatives.

By contrast, the data suggests only six per cent of Liberal and NDP supporters feel Poilievre would be the best pick.

The findings come as one of the main tasks facing Conservative leadership contenders, if they win, will be to grow support for the party ahead of the next federal election, particularly in seat-rich Ontario.

“The only way they can win back Ontario and do better in Quebec is to actually move voters away from the Liberal party and away from the NDP,” Bourque said.

Leger's data also suggests 57 per cent of respondents who support the more right-wing People's Party of Canada feel Poilievre should be the next Conservative leader.