OTTAWA - Debate continues today, with MP's expected to vote tonight on the Conservative government's proposal to extend its military campaign in Iraq for up to one year and authorize airstrikes in Syria.

Up to 69 special forces advisers will also remain in the region to advise and assist Kurdish peshmerga forces fighting the advance of Islamic State militants.

The Conservatives argue it is in Canada's national interest to join in military strikes against I-SIL targets, but some New Democrats maintain there's no proof I-SIL is in fact a domestic threat.

And the government has changed its thinking on the legality of flying missions over Syria.

After first stating it would first need President Bashar Assad's explicit consent, the government now says that I-SIL has been moving heavy equipment and personnel into Syria.

Foreign Affairs Minister Rob Nicholson says the militants cannot or should not be given a free ride just because we disagree with the government in Syria.

The Conservatives also argue the military mission will allow for aid to flow into more areas.

But the opposition says humanitarian support must be prioritized, with Liberal defence critic Joyce Murray urging the government to do more to help vulnerable refugee families.