David Cameron is set to discuss European reform with German Chancellor Angela Merkel during a visit to Germany.
In a highly unusual move, Mrs Merkel has invited the Prime Minister and his family to stay at her residence in Meseburg, outside Berlin, but Mr Cameron is expected to press on with talks on the EU.
Mr Cameron, who will be accompanied on the visit by his wife, Samantha, and their children, will talk over "all aspects" of European reform as well as the forthcoming G8 summit and the situation in Syria with Mrs Merkel, the PM's official spokesman said.
Mrs Merkel has made no secret of her concerns about Mr Cameron's plans to renegotiate Britain's relationship with the EU before staging a referendum on Britain's continuing membership.
No 10 said it was trying to reschedule a meeting with French President Francois Hollande after Mr Cameron pulled out of talks in Paris on Monday following the announcement of the death of Baroness Thatcher.
Earlier this week, Mr Cameron said British voters' support for EU membership was "wafer-thin".
In joint interviews with five European newspapers, he said the EU "sometimes overreached itself with directives and interventions and interference", and stressed the need for a "more flexible Europe". Mr Cameron said he was "convinced" there will be a need for treaty change in the EU but is facing resistance from France and Germany.
In January, the Prime Minister pledged a referendum on EU membership by the end of 2017 at the latest.
Michael Meister, deputy parliamentary chairman of Mrs Merkel's Christian Democratic Union party, said Germany was "open for arguments" about moving some powers back into the hands of member states.
"We want to unify Europe and we have to do it together, and I think there are a lot of common ideas with the British side and the German side on it," he told BBC Radio 4's Today programme. "It's a good thing that we have an idea of a private competitive economy and that's much different from other countries in Europe."