OTTAWA - Elections Canada has concluded that online vote-swapping schemes aren't illegal in themselves -- but it's warning voters to be careful what they're getting into if they decide to participate.

James Hale, a spokesman for the federal agency, said Wednesday that the simple act of encouraging someone to vote in a particular way is all right under the Canada Elections Act.

It's also permissible to invite people to participate in an organized strategic voting plan, whether on the Internet or by other means.

Nevertheless, said Hale, "electors should be cautious for a couple of reasons."

One is that they could potentially be misled by "someone acting under multiple or false identities to trick them into voting for a particular candidate."

In such a case, said Hale, the person who misled them would, in fact, be guilty of an offence under the Elections Act.

And even if a vote swap seems to be on the up-and-up, there's really no way of knowing for sure. That's because it's impossible to verify how people actually cast their ballots once they're in the voting booth.

Hale also cautioned that, under federal law, no money or other "material benefit" can change hands as part of a voting arrangement.

"Its not an offence to tell your friend you think they should vote in a certain way, and its not an offence to say `Yeah, I think that's a great idea.' It is an offence to accept money or to offer money for that."

Elections Canada started looking into the matter last week, after a Facebook group was set up with the aim of stopping Stephen Harper's Conservatives from winning a majority government on Oct. 14.

The site listed 41 ridings that will likely be tight races and encouraged members to swap votes in order to stop the Tories from winning those contests.

For example, a person in Parry Sound, Ont., might want to vote for the Green party but feel compelled to cast a ballot for the Liberals simply to stop Health Minister Tony Clement, who won by only 28 votes last time, from gaining re-election.

The person could use the site to find a Liberal in another riding where it would be safe to vote Green without fear of electing a Tory. The two would then agree to swap votes.

The Anti-Harper Vote Swap Canada group, set up by Mat Savelli of Hamilton, Ont., attracted more than 300 members from across the country within a day of its founding.

Savelli is currently in Romania working on a PhD in history but says he's planning on voting from abroad.