Chief electoral officer Marc Mayrand had been one of the strongest critics of the original bill.
He had 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 said Thursday many of his concerns have now been resolved by numerous amendments, which the government itself eventually proposed after the original bill was widely denounced by electoral experts at home and abroad.
"I think there's been substantive improvement to the legislation, especially with regard to vouching, the appointment of central poll supervisors, the fundraising exception also that has been eliminated," Mayrand said after testifying before a Commons committee about Elections Canada's spending estimates.
"So I think that there were significant improvements."
That said, Mayrand noted that "some matters" weren't addressed, in particular his long-standing request that the commissioner of elections be given the power to compel testimony during investigations into suspected violations of election laws.
"I am still worried that the commissioner doesn't have the tools that he needs to do a full investigation in a timely manner," Mayrand said.
Without the power to compel testimony, commissioner Yves Cote has said investigations will be impeded or aborted altogether.
In a recent report that concluded there was no Canada-wide conspiracy to use misleading automated phone calls to suppress votes in 2011, Cote said the investigation was impaired by unco-operative witnesses, some of whom refused outright to speak to investigators.
Among the amendments, the government agreed to a compromise on its plan to ban the practice of vouching for voters without proper identification. All voters will have to show proof of their identity but those without ID showing proof of address will be able to have someone swear an oath on their behalf.
The government also dropped its proposal to allow political parties to exempt the cost of soliciting donations from previous donors from their campaign spending limit. Experts had said the exemption would be unenforceable and would allow rich, established parties, particularly the governing Conservatives, to spend untold millions more during campaigns.
Another proposal to have party involvement in the appointment of central poll supervisors, was similarly dropped, and limitations on the chief electoral officer's ability to communicate with the public were loosened and clarified.
The amended bill was passed by the House of Commons last month.
Mayrand's criticism of the original bill triggered an unprecedented public war between the independent elections watchdog and the government. Pierre Poilievre, the minister responsible for democratic reform, at one point accused Mayrand of wearing "a team jersey," and of wanting to pad his power and his budget.
But just as Mayrand extricated himself from that controversy Thursday, MPs on the Commons procedure and House affairs committee seemed intent on dragging him into another: the dust-up over the NDP's allegedly improper use of Commons resources to mail almost 2 million partisan missives to households in 26 different ridings.
NDP MP David Christopherson asked Mayrand to clear up the perception that Elections Canada is investigating some of those mass mailings, which arrived in four ridings in the midst of byelections late last year.
Mayrand did not oblige. He noted that he has already told the multi-party board of internal economy, which oversees Commons spending, that the mailings did not constitute a byelection campaign expense because they were posted just before the writs were dropped.
However, he noted that the board has since asked him to take another look and determine whether the mailings amounted to illegal non-monetary contributions to the NDP byelection campaigns.
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