By an overwhelming majority, Britain joins the fight against Islamic State militants in Iraq.
Until this week France was the only Western country to answer President Barack Obama's call to join the U.S.-led campaign.
But Australia, Belgium and the Netherlands have all joined since Monday and Denmark announced on Friday that it too would send planes.
Obama has sought to rally international support for a military coalition against Islamic State, a powerful force in Syria which swept through much of northern Iraq in June, slaughtering prisoners and ordering Shi'ites and non-Muslims to convert or die.
The coalition also includes several Arab states, all led by Sunni Muslims alarmed at the rise of Islamic State.
