UK demands treaty guarantees on eurozone relations

"We want to design a simple mechanism to ensure the principles are enforced," he said, calling for "the kinds of checks and guarantees that exist in other parts of the EU’s governing rules."

Such a move would necessitate EU treaty change, despite strong reluctance from Britain's partners.

A few days before prime minister David Cameron is due to detail UK demands for EU reforms in a letter to other EU leaders, Osborne assured that Britons want "Britain to remain in a reformed European Union."

Regulations

In his speech addressed to German business leaders, Osborne focused on the single market and competitiveness.

"We need to make Europe more competitive, make this the place to start and grow a business, ensure the policies of the EU make us the home of jobs and growth and innovation," he said.

"Do that and we will go a long way towards reconnecting the EU with the support of its citizens – including the citizens of Britain. That is the change we seek, and we want your help to achieve it," he told his German audience.

"Some of Europe’s self-imposed regulations and rules have actually made this continent a less competitive place to run a financial services business," he pointed out, reminding that while services make up 80% of Britain’s output, they also make up 70% of Germany’s output.

But the message of George Osborne, who is considered as David Cameron's most likely succcessor, was also intended for other EU leaders waiting for clues on British intentions.

The EU where the British government wants to stay "needs to be a European Union that works better for all the citizens of Europe – and works better for Britain too," Osborne said.

For a start, he said, "it needs to be a Europe where we are not part of that ever closer union you are more comfortable with."

"Remain or leave, it is the question our democracy has demanded we put because, quite frankly, the British people do not want to be part of an ever closer union," he warned.

On the issue of EU migration, which is one of the main argument of Brexit supporters, Osborne said that "if freedom of movement is to be sustainable, then our publics must see it as freedom to move to work, rather than freedom to choose the most generous benefits."

He also said that "if politicians are to be accountable then we’ll need to strengthen the role of national parliaments."

'Here's the deal'

In several references to the current EU Commission's work, Osborne also signaled fields in which his government could be satisfied with ongoing policies, provided they go further.

"[Commission president and vice-president] Jean-Claude Juncker and Frans Timmermans and others have succeeded in reducing the amount of new regulation coming out of the Commission by 80%. It’s a real achievement that we should acknowledge," he said. But he added that "the existing body of European regulation" should now be tackled with "clear targets for doing so, and powerful mechanisms for delivering them."

Osborne also acknowledged steps towards the capital markets union and the latest internal market strategy but added: "now let’s turn a strategy document into reality."

In his speech delivered in Berlin, Osborne also looked for Germany's support in the upcoming negotiations.

"Here’s the deal," he told the audience: "you get a Eurozone that works better. We get a guarantee that the Eurozone’s decisions and costs are not imposed on us. You get a stronger Euro. We make sure the voice of the pound is heard where it should be. A deal that’s written into the law.

That would be "a deal that’s good for Britain. And a deal that’s good for Germany too," he added.

"The result will be a better European Union."

Speaking at the same event before the British minister, German chancellor Angela Merkel gave her backing to some British demands.

“Where there are justified concerns – whether competitiveness or a better functioning of the EU – British concerns are our concerns,” she said.

“The Europe of today is no longer a one-speed Europe,” she added. But she did not specify if Germany's concerns and flexibility would include setting in stone guarantees for non-euro countries.