David Cameron says he is “hopeful” of reaching a deal with European leaders in February that will allow him to hold the UK’s EU referendum.
The prime minister said the in-out vote “would follow” if agreement was reached on his reforms at next month’s summit.
He also said he would stay on as PM even if he ended up on the losing side.
He told Andrew Marr he did not think a UK exit was “the right answer” but promised “everything necessary to make it work” if there was a vote to leave.
The in-out referendum has been promised by the end of 2017.
Asked whether he was suggesting the referendum could be held this summer, Mr Cameron said: “That is what I would like to see, is a deal in February, then a referendum that would follow”.
It would take place “later” if no agreement was reached, he said.