Liberal MP Navdeep Bains is given a standing ovation MPs in Ottawa yesterday. Bains requested an apology from Stephen Harper after comments linking him with the Air India case.

Prime Minister Stephen Harper stands accused of sinking to new political lows in his battle with the Liberals, after trying to link Brampton MP Navdeep Bains to the ongoing criminal investigation into the Air-India bombing.

In the Commons yesterday, the Prime Minister was halted in his tracks with cries of "shame, shame" when he tried to read aloud from a newspaper story that exposed Bains’ father-in-law as someone the RCMP interviewed in connection with the 1985 bombing of an Air-India jet.

"The Vancouver Sun has learned that the father-in-law of the member of Parliament for Mississauga-Brampton…" — and that’s as far as the Prime Minister got before he was drowned out with a chorus of outrage on the Liberal benches.

It escalated from there and will likely remain as a storm cloud in Parliament today. As tempers in the House rose though, Harper, his advisers and his ministers started to back-pedal, arguing that he wasn’t trying to attack Bains.

Harper and the Conservatives say that Liberal opposition to extending special provisions in the Anti-Terrorism Act, which they themselves wrote, makes them soft on terrorism. It was in that context that Harper tried to launch his salvo yesterday.

The incident has reignited Liberal anger over what they see as the Tories’ preference for low-road campaigning against leader Stéphane Dion and former finance minister Ralph Goodale.