A Conservative health minister has a substantial financial stake in a private health screening and Covid testing firm, raising questions about the potential for a conflict of interest. Nick Markham, a businessman who was given a peerage under Liz Truss and appointed to the health department, owns about 30% of Cignpost Investments and has done so throughout his first four months in the job. The company was set up during the pandemic to provide Covid testing and health screening services to the private sector. Markham’s biography for the Department for Health website makes no mention of his private health sector interest, despite describing his previous private sector jobs at ITV and TopUp TV and as the founder of a charity. Markham was made a health minister in September and declared the Cignpost investment on his register of interests in the House of Lords. Ministerial interests are meant to be overseen by an independent adviser but the post has been vacant for six months since Lord Geidt resigned under Boris Johnson. Labour and the Liberal Democrats said it was not appropriate for a government minister to hold such a stake. Angela Rayner, Labour deputy leader and shadow chancellor of the duchy of Lancaster said: “Conservative cronies have been rewarded with peerages and plum ministerial jobs while maintaining lucrative interests. There is a rotten stench about the revolving door the Tories have left wide open. Labour will clean up politics by restoring standards in public life with an independent ethics and integrity commission.” “These interests are not just inappropriate, but downright unethical,” said Sal Brinton, the Lib Dem health spokesperson in the House of Lords. “The rules say that ministers should remove any conflicts of interest to prevent any influence on their judgment and maintain the public’s trust. Our minister should be held to the highest standards, but these are slipping with each new appointment. “Lord Markham should dispose of these interests and Rishi Sunak must immediately appoint a new ethics adviser.” Cignpost did not win any government contracts during the pandemic but it expanded its business as a result of the policy of requiring people to test regularly and the move from free to paid-for testing. Its subsidiary, Cignpost Diagnostics, made a pre-tax profit of about £15m on revenue of £49m in the year to March 2021, its first nine months of operation. Markham also owns stakes in a family investment company and a management consultancy firm, according to his register of interests. The Department of Health and Social Care had no comment when asked what was being done to mitigate the risks of a conflict of interest. However, it is understood that Markham has told the department that he is now in the process of divesting his shareholding. He resigned as a director when he became a minister in September. Markham’s health firm stake is the latest in a string of cases where ministers have been appointed despite direct financial interests related to their jobs, in contrast to historical precedent. Jacob Rees-Mogg was allowed to keep his shareholding in Somerset Capital Management, an asset manager, when he was business secretary and Chris Philp was allowed to keep a substantial stake in a property finance group and a role as a director of an investment company. At the time, Philp was Treasury minister with responsibility for spending policy in relation to housing and planning.