Britain's Prime Minister David Cameron stands in front of former Prime Minister John Major at the Remembrance Sunday ceremony at the Cenotaph in central London, November 8, 2015. REUTERS/Toby Melville

LONDON (Reuters) - Prime Minister David Cameron favors holding a referendum on Britain’s European Union membership in June next year if leaders of other member states agree to the bulk of his reform plans at a December summit, The Times newspaper reported on Monday.

Cameron has promised to renegotiate Britain’s ties with the 28-nation bloc ahead of a membership vote by the end of 2017.

Cameron’s office said the government had not made any decisions on the date of the vote. “As the Prime Minister has said, what will determine the timing of the referendum is the outcome of the negotiation, within the deadline of the end of 2017.”

On Tuesday he is due to publish a letter to the President of the European Council, Donald Tusk, outlining his reform demands. He will also warn that if no deal can be reached, he could back a British exit.

Citing officials, The Times said EU allies had been told that if a December summit of EU leaders goes well, Cameron would prefer to hold the referendum in June 2016. It said he had been persuaded by other EU leaders that the vote should not be delayed, with another migration crisis likely next summer.

Opinion polls show most Britons favor staying within the EU although support for remaining versus leaving has narrowed in recent months, with many voters citing concerns over migration.