Steve Barclay is a Tory MP, the chief secretary to the treasury and a former Brexit secretary under Theresa May and Boris Johnson.
Louise Haigh is a Labour MP and the shadow policing minister.
Pete Wishart is an SNP MP and the party's shadow leader of the House of Commons as well as the chair of the Scottish affairs select committee.
Richard Walker is the managing director of the supermarket chain Iceland Foods. He previously called for a second Brexit referendum.
Professor Ashton is the former director of public health in the north west and former professor of public health at Southampton University and the London School of Hygiene and Tropical Medicine.