The Harper Conservatives were caught off guard.

The Opposition New Democrats used a tactical play to force a debate in the Commons about the need for an inquiry into missing and murdered aboriginal women.

The NDP waited until most Tories had left the House after Question Period, then rushed their own members back in and out-voted the remaining Tories — approving the debate.

Prime Minister Harper has repeatedly rejected calls for an inquiry, saying it’s a criminal matter being handled by police.