TORONTO - Canada's ability to comply with its international obligations could be compromised if a decision staying the extradition of Abdullah Khadr is allowed to stand, the federal government said Friday.

In asking the Supreme Court of Canada to take up the case, Ottawa argues the lower courts were wrong to prevent an "admitted" terrorist from facing trial in the U.S.

"This case raises issues of national importance that require consideration by this court," Ottawa states in its leave-to-appeal request obtained by The Canadian Press.

Principles of fundamental justice "should not be used to impose the technicalities of our criminal law on a foreign partner."

In an interview, Khadr's lawyer Dennis Edney said he was "not surprised" Ottawa was seeking leave to appeal.

When it comes to the Khadr family, the government has consistently fought "strong" Appeal Court rulings only to lose before the Supreme Court, Edney said.

"All this at the expense of the public purse," he said.

Last August, Ontario Superior Court Justice Christopher Speyer decided there were sufficient grounds to send Khadr to the U.S. based on self-incriminating statements he'd given the RCMP.

However, Speyer stayed the extradition, saying the United States had violated fundamental justice with its involvement in Khadr's "shocking" mistreatment during 14 months detention in Pakistan.

Extraditing him would only serve to reward what he called the Americans' "gross misconduct," Speyer said.

In May, the Ontario Court of Appeal upheld Speyer's ruling.

Judges are not required to sacrifice important legal rights and democratic values to ensure a proceeding against an alleged terrorist goes forward, the Appeal Court decided.

In its memorandum of argument to the Supreme Court, Ottawa says Speyer failed to weigh the impact of extraditing Khadr versus the effects of stopping the extradition.

"The unique circumstances of terrorist crimes militates in favour of always conducting a balancing between the benefits of granting a stay against the benefits of ensuring that alleged terrorists face trial," the memorandum states.

Ottawa also maintains the Appeal Court wrongly expanded the limits of extradition judges.

"It has done so in vague terms that will lengthen 'expeditious' extradition proceedings, potentially frustrating Canada's ability to comply with its international obligations," it says.

In a prepared response to Ottawa's memorandum, Edney calls the feds' appeal case "entirely devoid of merit."

"Its present application fails to identify even an arguable ground of appeal, much less a legal issue of public importance," Edney says

"Another appeal . . . would be a waste of this court's resources."

In October 2004, the U.S. paid Pakistani intelligence agents $500,000 to kidnap Khadr.

He was prevented from speaking to consular officials and beaten until he co-operated with Pakistani intelligence.

American agents also interrogated him in Pakistani detention and got him to admit he had procured weapons for al-Qaida.

An American intelligence agency sponsored Khadr's "kidnapping, beating and 'disappearance,'" Edney says in arguing against a Supreme Court hearing.

The Pakistanis freed Khadr without charge and he returned to Canada in December 2005.

Khadr is the oldest son of the late Ahmad Said Khadr, who was closely associated with Osama bin Laden.

He is also is the brother of convicted war criminal Omar Khadr, who is currently held at Guantanamo Bay and who has also been the subject of losing appeals by Ottawa to rulings in his favour.