The British and German economies are the "beating heart" of Europe, George Osborne has insisted as he heads to Berlin for talks on reforming Brussels.
In discussions with senior ministers, the Chancellor will warn that despite the joint economic power of the two nations, action must be taken to overhaul the European Union to protect against future challenges.
Securing backing from Germany is crucial to the success of the plans to renegotiate Britain's relationship with the European Union and Prime Minister David Cameron has keenly courted support from Chancellor Angela Merkel.
Mr Osborne, who will meet finance minister Wolfgang Schauble and federal economic affairs minister Sigmar Gabriel, said: "The UK and German economies are the beating heart of Europe, the engine for growth and jobs.
"Together we make the world's third-largest economy, behind only America and China and since the crisis ended, we have generated two-thirds of EU growth.
"But the future holds challenges for our economies. We must cut debt and boost productivity. To do this, we need a strong EU, fit for today's challenges and working for the benefit of all 28 member states.
"The UK's reform and renegotiation plans aim to achieve this, which is why these talks with key partners in Europe are so important."
Mr Osborne will also visit a Siemens factory in the German capital and address an audience of business leaders at the annual conference of the BDI, the Federation of German Industries.
It follows "positive" talks with ministers in Helsinki, Stockholm and Copenhagen to build support for the UK's demands for a new settlement earlier this year.