Parliament Hill in Ottawa may present many bizarre spectacles. But has the wide, green lawn in front of the Parliament Buildings ever seen something as bizarre as a demonstration in support of a convicted "human bomb?"

That's what happened on Wednesday when several hundred Canadian Sikhs bused to Ottawa to demand clemency for an admitted terrorist named Balwant Singh Rajoana. Rajoana, on death row in India, must surely be the most unlikely poster boy for a "human rights campaign" that the Canadian capital has ever seen.

In India, the term "human bomb" denotes a suicide bomber — although Rajoana only aspired to blow himself up and never pressed the button. But he proudly acknowledges that he was the backup bomber, ready to step in if the lead bomber failed in the 1995 assassination of his fellow Sikh, Beant Singh, chief minister of the state of Punjab.

Seventeen others died as collateral damage. Rajoana, sentenced to death in 2007, claimed to have directed the attack as a member of the Babbar Khalsa, the banned terrorist group whose Vancouver cell is blamed for the Air India bombing of 1985. The BK was one of several underground groups fighting for a separate Sikh state in Punjab.

On death row, Rajoana waived his right to appeal, refused to ask for clemency and said he wished to "die as a martyr" for the Sikh cause. His hanging was set for Saturday, March 31. But, on Wednesday morning, facing strikes and demonstrations all over Punjab, the Indian government ordered a stay of execution.

This was not enough for the demonstrators in Ottawa, who consider Rajoana a "living martyr" and a "political prisoner." They cloaked their rally in the banner of "human rights" and a spokesman for the Canadian Sikh Coalition, Moninder Singh Bual, urged Sikhs to "liberate the thousands of Sikh political prisoners facing a similar plight to Bhai Rajoana."

"Bhai," meaning brother, is a term of esteem given to Sikh priests and other respected figures.

Convicted killers have often received such praise throughout the long history of Sikh extremism, in which Canada has always played an important role. And, if there were any doubt that Canada remains a stronghold of Sikh separatism, Wednesday's demonstration should settle it.

The Air India bombing may have been 27 years ago, but a low-level struggle goes on and, for weeks, a campaign has been waged to draw political figures into the defence of Rajoana and the condemnation of the government of India.

In the past, such efforts have often succeeded. Large and politically energetic Sikh communities in B.C. and Ontario present rich pickings for the pandering politician. Over the years, Conservatives, Liberals and New Democrats have all been caught cozying up to Sikh extremists in pursuit of donations, endorsements and votes.

But this tendency fell into disrepute in 2007, when politicians from all parties were spotted applauding a Vaisakhi parade float in Surrey, B.C., bearing the garlanded portrait of the "martyred" Talwinder Singh Parmar, the architect of 331 deaths in the Air India bombing. At the Air India inquiry under retired justice John Major, relatives of the victims reserved special scorn for this spectacle.

"I'm sorry, I know it's about your votes, but that's dirty business," Perviz Madon testified. Her husband, Sam, died in the bombing.

"You don't want to be associated with a group that is linked to terrorism," she went on. "You don't want those kind of votes!"

Of course, the appetite for votes has not disappeared. During the 2011 campaign, extremist voices again clambered onto the political stage in pursuit of respectability and influence. But the defence of Rajoana may have been too much to swallow.

Jasbir Sandhu and Jinny Sims, two NDP MPs from B.C., gave minimal assistance to the Rajoana campaign by issuing a press release condemning capital punishment. But they kept clear of any sympathy for Rajoana himself and neither spoke at the rally on Parliament Hill. Liberal MP Jim Karygiannis did speak there but made the same point and, like the two NDPers, condemned political violence.

Several other MPs spoke to the rally later in the afternoon, including Conservative Parm Gill, Liberals Bob Rae, Irwin Cotler, Justin Trudeau and Kirsty Duncan, and the NDP's Jasbir Sandhu, Wayne Marston and Don Davies. All spoke against the death penalty.

So it may be that the influence of Sikh extremists is fading. But they're certainly not giving up. And, for now, they've ensured that the "human bomb," Balwant Singh Rajoana, lives on.