Who's in and who's out on Britain's EU referendum campaign

Harriet Harman, Labour's acting leader, announced on Sunday morning that the party will back an EU referendum taking place before the end of 2017, but will campaign for the country to stay in the union.

With news also emerging that Eurosceptic MPs are trying to woo Lynton Crosby - the Conservative party's chief election strategist - the Independent on Sunday has compiled this guide to who's on which side in the In/Out referendum:

IN

YES 2 EUROPE

This umbrella organisation will include British Influence, Business for New Europe and the European Movement. Yes 2 Europe will plan to get ahead of its rivals by formally launching next month.

PEOPLE

British Influence already has an array of cross-party figures, including Lord Mandelson, the former Labour Cabinet minister and EU commissioner; Kenneth Clarke, the former Tory chancellor; and Danny Alexander, the ex-Lib Dem MP who was formerly an official in the pro-single currency Britain in Europe group and could use his new-found free time to fight for a Yes vote. The advisory council of Business for New Europe includes chairmen and chief executives of FTSE 100 companies.

BUSINESS AND INDUSTRY

Confederation of British Industry chief Sir Mike Rake has called for businesses to be more vocal in support of the UK’s ongoing membership. Other major firms backing the Yes side are EEF, Airbus and BT, whose boss Gavin Patterson has warned that the EU referendum is “bad for business”. Most trade unions are in favour of staying in.

POLITICS

David Cameron will fight for a Yes vote if he secures reforms with Brussels. There is also a substantial group of Conservative MPs, led in Parliament by former minister Damian Green under the group European Mainstream, and most of the Labour Party, including all four leadership candidates; the Liberal Democrats, including Nick Clegg, who would be a passionate advocate if he agreed to take a prominent role. The SNP is concerned that Brexit could destroy Scotland’s economy and would likely demand a second independence referendum in those circumstances.

OUT

CAMPAIGNERS

Matthew Elliott, who founded the TaxPayers’ Alliance, heads the leading “Out” group, Business for Britain. Conservative Philip Davies and the Democratic Unionist Party’s Jeffrey Donaldson are among the MPs who back Better Off Out, a cross-party campaign group led by Rory Broomfield. The largest grassroots campaign is called Get Britain Out, a five-decades-old group that was previously known as the Anti-Common Market League.

LAUNCH

An umbrella group for the various “Out” campaigns is expected to launch in early September, although it would have to pay big money if it wants to get Lynton Crosby to advise it: he was on a £500,000 deal with the Conservatives.

BACKERS

In the media, the campaign will be backed by the Express newspaper titles, which are owned by Ukip supporter Richard Desmond. Campaigners are trying to play down Ukip’s role, fearing that Nigel Farage might put off floating voters unhappy with his views on immigration. Many hedge fund managers infuriated by the EU’s regulatory clampdown on financial services are likely to want an exit: hedge fund boss Crispin Odey is a financial backer to Ukip.

PUBLIC OPINION

The “Out” campaign has started to lose ground, with only 35 per cent wanting exit against 45 per cent for staying in, according to a YouGov poll last month. It held a brief lead last year.

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