British Defence Secretary Philip Hammond has said that he would vote for the UK to the leave the EU – if a referendum was held now.
But he added that prime minister David Cameron should be allowed to try and renegotiate powers before any vote is held.
His comments came after Education Secretary Michael Gove said that he would also back an EU exit.
Cameron has pledged to hold a referendum in 2017, if the Conservatives win the next election.
A group of backbenchers want to see that pledge firmed up with legislation – which did not happen in last week’s Queen Speech. Now the rebel MPs are planning to table a motion, which could be voted on later this week.