A ban on early broadcasting of election results that dates from the 1930s puts Canada on a collision course with social media like Twitter and Facebook, making a scofflaw of anyone who tweets too soon.

Canada goes to the polls on May 2 and critics say the ban -- which was introduced in the days when radio was king -- is totally unenforceable in an age when millions of people have access to the Internet.

As the law stands, nobody can even tweet election results from Eastern Canada before polls close in the Pacific province of British Columbia up to three hours later. Canada has six tine zones.

Elections Canada, the agency that runs elections, reminded media this week of rules designed to prevent voters in the West from being influenced by results in the East.

Newspapers cannot update their websites with early results, broadcasters must stagger their reporting to be sure results go only to parts of the country where the polls have already closed and violators face fines of up to C$25,000.

This will be unenforceable by Elections Canada, and if they intend to fine everyone on Twitter who breaks the rules they will have a good financial year, said Eric Grenier of the popular ThreeHundredEight.com political website.

Grenier told Reuters he would play it safe and not start issuing results until the final poll had closed, although it's not clear whether U.S.-based bloggers will do the same.

The rule banning premature transmission of results is in stark contrast with the situation in the United States, where Californians often know the outcome of a presidential election while they still have a chance to vote.

Paula Simons, a columnist for PostMedia News, said the result blackout was not only a condescending relic of the 1930s that treats voters like sheep, but also an unenforceable law that criminalizes routine social media conversation.

Others wonder how Elections Canada could possibly clamp down on thousands of people tweeting and Facebooking results from the East.

The agency, which says it is obliged to enforce the law, does not monitor for transmission breaches and can only start an investigation if someone complains.

We haven't seen any of this activity, so it's still hypothetical right now, said spokesman John Enright.

But if we were on election day and somebody was posting results to their Facebook user's wall, that would very likely be considered ...to be public transmission.

Prominent conservative blogger Stephen Taylor said the rule was not grounded in the new reality of Twitter and Facebook.

Elections Canada ... really ought to close the polls at the same moment across the country or keep all polls sealed and start counting at the same time, he told Reuters.

Former Canadian chief electoral officer Jean-Pierre Kingsley, now a professor at the University of Ottawa, told Reuters the initial ban and the system of staggered voting times were introduced for a good reason.

Western Canadians were complaining to the politicians, they were complaining to Elections Canada, saying 'The results are already known, why should I go and vote?', he said.

He said closing ballot boxes at a fixed hour or starting the count at the same time would mean too much work for tens of thousands of volunteers already working long hours.

One of the fundamental values of a good electoral system is to get the damn results out as soon as possible, he said.

($1=$0.95 Canadian)

(Reporting by David Ljunggren; editing by Peter Galloway)