Conservative party

Richard Balfe– former MEP and Conservative Party Envoy to the Trade Unions and Cooperative movement

Sir Anthony Bamford DL – Chairman and Managing Director of JCB

Nicholas Bourne – former Leader of the Conservative Group in the National Assembly for Wales

Matthew Carrington – former Conservative MP

Daniel Finkelstein OBE – Associate Editor of The Times and former Head of Policy for the Conservative party

Annabel Goldie DL MSP – Conservative Member of the Scottish Parliament; former Leader of the Scottish Conservatives

Lady (Fiona) Hodgson CBE – campaigner on women’s issues; senior member of the Conservative voluntary Party; former Chairman of the Conservative Women’s Organisation

Christopher (Chris) Holmes MBE – former Paralympic swimmer; Director of Paralympic Integration at London 2012; Non-Executive Director of the Equality and Human Rights Commission; and a former Non-Executive Director of the Disability Rights Commission

John Horam – former MP; Conservative representative on the Electoral Commission

Howard Leigh – senior corporate finance professional; Conservative Party Treasurer; former Chairman and current President of Westminster Synagogue; former Trustee of Jewish Care and current Chairman of Jewish Care’s Business Group; Trustee of the Jerusalem Foundation in the UK

Dame Lucy Neville-Rolfe CMG – former senior civil servant, including Number 10 Policy Unit; former leading Executive at Tesco Plc

Sir Stephen Sherbourne – longstanding political career in Westminster and public affairs, including former Political Secretary to the then Prime Minister (Margaret Thatcher), and former Chief of Staff to the then Leader of the Opposition (Michael Howard)

Michael (Mike) Whitby – Conservative Councillor in Birmingham; former Leader of Birmingham City Council

Susan Williams – former Councillor and Leader of Trafford Council

Green party

Jenny Jones AM – member of the London Assembly; former Chair of the Green party of England and Wales and former Deputy Mayor of London

Labour party

Sir Charles Allen CBE – Non-Executive Director of the London Organising Committee of the Olympic and Paralympic Games; Chairman of Global Radio Group

Sir William Haughey OBE – prominent Scottish businessman and CEO of City Refrigeration Holdings

Alicia Kennedy – former Deputy General Secretary of the Labour party

Doreen Lawrence OBE – campaigner for justice, race equality and better policing

Jonathan (Jon) Mendelsohn – business advisor and co-founder of LLM Communications

Liberal Democrat party

Catherine (Cathy) Mary Bakewell MBE – former leader of Somerset County Council

Rosalind (Olly) Grender MBE – former Director of Communications for Shelter; former Director of Communications for the Liberal Democrats

Christine Mary Humphreys – President of the Welsh Liberal Democrats; former Member of the National Assembly for Wales

Zahida Manzoor CBE – former Legal Services Ombudsman; former Deputy Chair of the Commission for Racial Equality

Brian Paddick – former Deputy Assistant Commissioner in the Metropolitan Police Service

James Palumbo – co-founder and chairman of Ministry of Sound Group, the international music and entertainment business

Jeremy Purvis – former Member of the Scottish Parliament for Tweeddale, Ettrick and Lauderdale

Alison Suttie – former Press Secretary to the President of the European Parliament; former Deputy Chief of Staff to Nick Clegg and Election Manager for the 2010 General Election

Rumi Verjee CBE – entrepreneur and philanthropist

Sir Ian Wrigglesworth – Liberal Democrat Treasurer; former MP for Teeside Thornaby and for Stockton South