Britain’s Chancellor will outline how he wants to protect London’s financial services industry in a reformed European Union (EU) when he travels to Germany next week.

Prime Minister David Cameron is trying to convince other EU leaders to agree to changes in the way the 28-country bloc is run ahead of Britain’s in-out membership referendum which is due to be held by the end of 2017.

“We are now starting to negotiate directly with our colleagues in Europe through the European Council and setting out more detail of what we think is required,” Chancellor George Osborne said on Friday in York.

Osborne said that in Berlin he would add details of how the British government hopes to achieve its twin aims of addressing the concerns of voters at home about the relationship with Europe, whilst convincing European peers that British-led reforms will improve the bloc.

Polls show British voters are largely split on whether to leave the bloc, with a small majority currently saying they would vote to stay a member.

In talks with his German counterpart Wolfgang Schaeuble, Osborne, one of Cameron’s lead negotiators in Europe, is expected to explain Britain’s fears that ever-closer integration of the euro zone could leave London sidelined in financial policymaking, affecting its banking sector.

Protection for states in the EU but outside the 19-member single currency area is a key priority for Britain, whose financial services industry accounts for around 8 percent of the economy.

The Financial Times, citing unnamed European ministers and officials, reported that Britain is seeking an “emergency brake” to allow countries which are in the EU but outside the euro zone to delay decisions that could threaten their interests.

Cameron has sought to defuse frustration among fellow EU leaders over a lack of detail on his demands for new EU membership terms by promising to send them his wish-list in writing in early November.

Cameron’s spokeswoman said on Friday that a letter outlining the reform plans is likely to be sent in the week commencing Nov. 9.

When asked about the possible timing of the vote, Osborne said: “We will hold the referendum when we have a deal we can recommend to the British people.”