British Prime Minister David Cameron is planning to send voters a dossier on the benefits of European Union membership ahead of an in-out referendum, British media reported on Sunday.

Under pressure from eurosceptics within his ruling Conservative party and many Britons, Cameron is currently renegotiating Britain’s relationship with the EU ahead of a referendum expected by the end of 2017.

Some media reports have said the vote could come as early as the middle of next year.

Citing unnamed sources, Britain’s Telegraph newspaper said Cameron was planning to issue a document outlining the “changes, the benefits of the changes to Britain, and why therefore we need to stay in the EU”.

Cameron has not yet reached a deal with other EU members on changing Britain’s ties with the bloc.

The Telegraph said Mats Persson, the prime minister’s adviser on Europe and the former head of a think-tank on EU reform, revealed the plan to senior Conservatives in November.

Cameron’s Downing Street office denied it was trying to push voters into choosing to stay in the EU, but said it had a legal duty to produce “public information on the outcome of renegotiation”.

“It is absolute nonsense to suggest the government is working up a pro-EU pamphlet to send to families to discourage them from voting no in a referendum,” Downing Street said in a statement.

“We’ve always been clear that it is important that the British public are provided with the information they need to understand the consequences of their choice in the referendum.”

Cameron wants the EU to cut bureaucracy, and provide guarantees that Britain will be exempt from the EU’s goal of closer union and be protected from decisions made by the 19 EU members who use the euro currency.

Most contentiously, he also wants to reduce migration to Britain by curbing welfare payments to citizens of other EU countries, triggering opposition from several member states.