The other campaign groups

Vote Leave

Leader: Matthew Elliott, chief executive

What they want: Britain to leave the EU, with a campaign backed by a cross-party group of senior politicians

Key backers: Former Cabinet minister Owen Paterson, Steve Baker, chairman of Conservatives for Britain.

Business for Britain

Leaders: Matthew Elliott, Robert Oxley

What they want: To give a voice to Britain’s business community who want to see changes made to the terms of Britain’s EU membership

Key backers: More than 1,300 signatories including business chiefs Luke Johnson and Sir Rocco Forte

Conservatives for Britain

Leaders: Steve Baker MP, chairman; Lord Lawson, president

What they want: To explore how to reform the EU and change Britain’s relationship with it and to prepare for the “out” campaign

Key backers: More than 100 Conservative MPs, including some Cabinet ministers and Eurosceptic veterans such as Sir Bill Cash and John Redwood

Leave.EU

Labour Leave

Leader: Kate Hoey MP

What they want: To give Parliament back the right to make its own laws, with control of the UK economy

Key backers: Labour donor John Mills, senior Labour MPs

Britain Stronger in Europe

Leader: Stuart Rose, chairman

What they want: To keep Britain in the EU

Key backers: Business woman Karren Brady, former ministers Lord Mandelson, Damian Green and Danny Alexander