Liberal MP Judy Sgro says a mailout sent from the NDP's Mike Sullivan is an attempt to advance a partisan cause and potentially evade Ontario's campaign finance rules.
A copy of the pamphlet circulated to the media features a letter signed by Sullivan that calls for the removal of the HST from daily essentials and a pledge that the NDP will remove it from electricity and home heating.
That's a key plank of the Ontario NDP's platform in the current provincial election.
But Sullivan says it's a wider NDP issue that isn't limited to the provincial element of the party.
He says the federal NDP is also calling for a reduction in the HST, something he personally campaigned on during the last federal election.
Sullivan did not comment on the photograph of the provincial NDP candidate which also appears in the mailing.
Sgro says the pamphlet appears designed to achieve partisan goals, a violation of House of Commons rules.
She is calling on the Speaker of the House of Commons to investigate.
It's not the first time such mailings have caused controversy.
They're known as "10 percenters" because MPs once were able to send the pamphlets to voters outside their riding in numbers equal to 10 per cent of the MP's own riding.
But that element of the program was scrapped after an outcry over the increasingly partisan use of the taxpayer-funded resource.