In the pretty central square of Plzen (Pilsen), the Czech town famous for its lager, the Civic Democrats are doing their best to pull in a crowd.

As the politicians wait under vast blue umbrellas, party workers hand out blue and white balloons and blue candy floss to the crowd. The kids are captivated and the occasional mum or dad is persuaded to take a leaflet on the European elections.

This party, known here by its initials ODS, until very recently was the Czech government. And they're Mr Cameron's new best chums.

After the Euro elections in the first week of June he wants to form a new group in the European Parliament, breaking away from the Christian Democrat, pro-European integration, European People's Party. He'll need MEPs from six other countries to do it. The Civic Democrats and the Polish Law and Justice party will be the mainstay.