Germany's president is appealing to Britain not to turn its back on the European Union, while voicing understanding for its frustration with the EU.

President Joachim Gauck said in a speech today that only a more united Europe can be a global player.

That prospect is opposed by many in Britain, where Prime Minister David Cameron has offered a future referendum on whether to leave the EU.

Mr Gauck said of Britons: "We need your traditions, your soberness and your courage." He added: "More Europe should not mean 'without you.'"

Germany's presidency has little executive power but carries moral authority.

Germany, Europe's biggest economy, has often been criticised abroad for its approach to the debt crisis but Mr Gauck says no one there aspires to give orders to other countries.