Until August 2005, Britain in Europe was the main British pro-European pressure group. Despite connections to Labour and the Liberal Democrats, it was a cross-party organisation with supporters from many different political backgrounds. Initially founded to campaign for a “Yes” vote for the euro, it then progressed to support a “Yes” vote for the referendum on the Treaty establishing a Constitution for Europe.
The organisation was launched in 1999 by Tony Blair, Gordon Brown, Kenneth Clarke, Michael Heseltine and Charles Kennedy. In 2003, the organisation formally linked itself with the Brussels-based, pro-European, international organisation European Movement.
The director of Britain in Europe was Simon Buckby and later Lucy Powell. The director of communications was the Scottish Liberal Democrat politician Danny Alexander.
On 17 August 2005, the group was wound up following the French and Dutch "No" votes on the proposed European Constitution. Its resources were turned over to the European Movement.
A successor pro-EU campaign, founded in 2012, is British Influence.
Publications.
All are PDF files 
Backers.
The organisation disclosed the names of individuals and companies from which it received donations of more than £5,000, in line with the requirements of the Political Parties Act, although it was not a political party and was not obliged to do so.