Canada's elections watchdog says amendments have significantly improved the Harper government's controversial overhaul of election rules. Chief electoral officer Marc Mayrand was one of the strongest critics of the original bill.

He warned it could disenfranchise tens of thousands of voters, create a giant loophole that would make campaign spending limits unenforceable and muzzle his ability to communicate with Canadians.

But Mayrand now says most of his biggest concerns have been resolved by amendments, which the government itself eventually proposed after the original bill was near-universally denounced by electoral experts at home and abroad.

However, he says he's still concerned that the government has refused to give the elections commissioner the powers needed to fully investigate suspected breaches of election law.

The amended bill was passed by the House of Commons last month and is currently being examined by a Senate committee, which is not expected to recommend further changes.