Canada is considering deploying a second aircraft to support the mission in Mali, CBC News has learned, as Prime Minister Stephen Harper indicated he'd like to see a "broad consensus" across Canada about any help for the country.

The mission could last for months, sources tell the CBC's James Cudmore. But, they caution, the most pressing moments for the nascent international force in Mali are during these early days of the operation — and that's where Canada's efforts will likely be focused.

French military planners are desperate to surge gear and troops into Mali and deploy them forward to the fight. It's that effort Canada is considering assisting.

In such a scenario, Canadian air crew would be under the operational control of a French-led Coalition Air Operations Centre, that would co-ordinate all air support to the international mission.

The details of the contribution are still to be approved by the government and worked out among allied militaries.

A source tells CBC News the exact nature of Canada's contribution will depend on what other countries bring to the negotiating table. But in each case the negotiations are based on limited French requests for logistical support — not combat troops.

Allied militaries are discussing how best to build an African air bridge that would help supply French forces. But it would also bolster those forces by providing transport to thousands of African Union and Economic Community Of West African States (ECOWAS) troops and equipment on their way into Mali.

If that plan is agreed, Canada would contribute both a long-haul C-17 strategic airlifter and a shorter range C-130 Hercules tactical cargo plane.

'Broad consensus'

Canada is looking at whether and how to extend its help for Mali, but would like to see a "broad consensus" behind its efforts, Harper said Wednesday.

Canada has provided a C-17 Globemaster for one week to transport equipment and troops that are helping efforts to shut down an al-Qaeda-linked insurgency, which Harper says the government views "as a very important anti-terrorist mission."

He allowed that that time-limited commitment could be extended, pending consensus with the government's opposition in the House of Commons.

"I'm obviously talking to my colleagues, and we're also in consultation with the opposition parties," Harper said in Cambridge, Ont., where he was announcing federal funding for an auto-industry project.

"Anything we do, I'd like to see a broad Canadian consensus behind that. I do think it is important to help this mission. At the same time, I think we've been very clear, and I think this reflects Canadian opinion that, while we're prepared to help, we don't want to see a direct Canadian military mission to Mali.

"So we will continue to look at ways we can be helpful with a broad consensus in Parliament."

Commitment ends tomorrow

The current commitment for the transport plane ends Thursday. To date, the C-17 has been involved in daily shuttles delivering heavy equipment to Mali's capital, Bamako, from a military base in southern France.

Harper spoke to New Democrat Leader Tom Mulcair on Sunday and asked about extending the loan of the C-17, NDP foreign affairs critic Paul Dewar told CBC News.

The NDP wanted to ensure parliamentary oversight on what's happening in Mali, as well as an assurance that the foreign affairs committee will hold public meetings on the issue. Dewar said the government agreed to both.

It's important Canadians know what the problems are, as well as the options for helping, Dewar said.

"We know that right now there's hundreds of thousands of refugees that are in need of help. Can Canada help there? We think they can," he said.

House leaders for the Conservatives, NDP and Liberals are in talks about how to handle the debate, which could be a take-note debate that is non-binding.

Mulcair is fine with a simple extension, but believes the House should be informed, an NDP source told CBC News.

Last week, Mulcair told Evan Solomon, host of CBC News Network's Power & Politics, that he supports Canada's "limited approach" to send a C-17 military aircraft for one week to back the French-led mission in Mali — but he insisted that any broader contribution would need to be debated in the House of Commons.

"Anything else is going to have to go through Parliament," he said. "There's been no request for a special debate on that so far."

No 'boots on the ground'

MPs don't return to the House of Commons until Jan. 28, following several weeks off to allow them time in their ridings.

Liberal defence critic John McKay says Harper has also reached out to interim Liberal Leader Bob Rae.

McKay says it's up to Harper to make the case in Parliament for the mission and the extension, but that there's no need for a "thumbs up or down" vote on any possible extension of a logistical support mission.

McKay says it's wise to be reluctant to commit too much militarily to Mali, but he'd like to see Canada double down on humanitarian aid.

Defence Minister Peter MacKay, speaking in Halifax, hinted the government will soon make its plans public.

"We will not be committing boots on the ground, we will not be putting combat soldiers into this mission," he said.

"Having said that, it's been well reported that there have been other requests that are under consideration, and we'll have more to say about that in the near future."