Britain's defense minister says lawmakers should consider expanding Royal Air Force airstrikes against the Islamic State from Iraq into Syria.

Defense Secretary Michael Fallon told the House of Commons on Thursday that there was a case for taking action in Syria, but the government would "not bring a motion to this House on which there is not some consensus."

Britain's Parliament voted in September to attack militants in Iraq, but not Syria. Britain opposes the regime of Syrian President Bashar Assad.

Fallon said "any action we take must not provide any succor to Assad or Assad's regime." But he added that it was clear that I.S. activity "in Iraq and elsewhere — and probably in Libya — are being directed from northern Syria."

On Wednesday Fallon said "there is an illogicality" about not being able to strike IS positions in Syria, because the militants "don't differentiate between Syria and Iraq."

But Crispin Blunt, chairman of parliament's Foreign Affairs Committee, said British strikes in Syria would make "no practical difference" to the U.S.-led military campaign and would lead Britain into a legal gray area.

Vernon Coaker, defense spokesman for the opposition Labour Party, said Labour would consider backing Syria action, but it "must command the support of other nations in the region, including Iraq and the coalition already taking action in Syria."

No vote on the issue is scheduled, and Cameron's office said more deliberation was needed before a decision could be made.