Burnley MP Julie Cooper said she is yet to reach a decision on whether to back air strikes against Islamic State militants in Syria.
MPs will be asked to vote on whether military action in the Middle East should be extended to Syria by Prime Minister David Cameron in the wake of the terror attacks on Paris two weeks ago. But Mrs Cooper said she has more to consider before she reaches a decision.
"This is a massive decision. If I put my name to something that is going to kill people, I want to be sure.
"It should come with a full resolution from the United Nations Security Council. I'm back in Parliament on Monday and I will be having lots of conversations on this subject. I was shocked and horrified by the attacks in Paris but Paris was targeted because France has been bombing in Syria.
"We don't just want to run in there and start bombing. In the past we've got it wrong. We've never had a successful bombing campaign in the Middle East. I don't want people to go shopping in Manchester and risk an attack."
Mrs Cooper added that the Labour Party is split between those who are against air strikes and those who would back military action. The Prime Minister has yet to set a date for the Commons vote.