Earlier, the prime minister said he “remained committed to parliamentary convention” that, where possible, military action should be debated by MPs.
He said in this case, it would have affected the security of the operation to consult the House of Commons before the strikes.
In 2011 the-then government acknowledged “a convention exists” that MPs should be consulted. But convention does not mean obligation. The PM still has the power to launch military action without a debate in Commons.
Since 2011, MPs have sometimes voted on military action, and sometimes not.
Most famously in August 2013 the government was defeated on taking action against the Assad government in Syria over the use of chemical weapons. As a result, the action did not go ahead.
MPs also debated actions against ISIS in Iraq in September 2014 and on extending military action against ISIS in Syria in December 2015.
But MPs were not consulted in April 2018 when airstrikes were launched in Syria against the Assad government. And in January 2013 there was no vote on deploying military aircraft and personnel to support French troops in Mali, although they played no combat role there.