Del Mastro was convicted of exceeding spending limits during the 2008 election, failing to report a personal contribution of $21,000 to his own campaign and knowingly submitting a falsified document.
"There is fresh evidence that was not put before the trial judge because it was not disclosed in a timely fashion by Elections Canada," he said Monday in a statement.
Del Mastro, who insists he didn't break any election laws, wants the defence re-opened before his Nov. 21 sentencing date.
He says new evidence can be introduced if it is relevant, credible, capable of changing the result of the trial and could not have been presented during the trial.
The now-Independent MP — a former parliamentary secretary to Prime Minister Stephen Harper — faces a maximum penalty of one year in jail and a $1,000 fine on each charge, as well as the prospect of losing his House of Commons seat.
His future as an MP rests with the Commons, where the matter has been referred to a committee.
During question period Monday, New Democrats used the case as a bludgeon against Harper and the Conservatives.
NDP House leader Peter Julian said Harper's judgment is in question because he made Del Mastro his personal spokesman.
Del Mastro spent a lot of his time as parliamentary secretary fending off complaints about alleged underhanded electoral tricks on the part of the Conservatives.
Julian said the court verdict shows the Conservatives "will do anything to win, even violating the law repeatedly."
Paul Calandra, Harper's parliamentary secretary, said it's a matter for the committee.
"My understanding is that any further measures with respect to this will be considered by the standing committee on procedure and House affairs," he said. "They have a good ability to undertake this kind of investigation."
After the verdict was delivered last week, Del Mastro said the case wasn't over.
"I've always maintained and I maintain ardently that I've in no way broken any of the laws governing elections," he said.
"I would suggest we're going to take a very hard look at this ruling and we'll come up with a plan going forward."
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