Obama says stay, but some Cameron MPs prepare to back UK exit from EU

By Michael Holden and William James LONDON (Reuters) - More than 50 lawmakers in Prime Minister David Cameron's Conservative Party launched a campaign to back Britain's exit from the EU unless he can get it to adopt radical reforms, even as U.S. President Barack Obama argued in favour of staying. Cameron, riding high after a surprise outright victory in last month's parliamentary election, wants to claw back powers from the European Union before holding a referendum by the end of