Labour has asked the government and the Conservative party to publish details of meetings that ministers, MPs and officials held with Tory-linked companies that were subsequently awarded public contracts connected to coronavirus, saying the information was vital for public trust. In an escalation of Labour’s efforts over what it says is rampant cronyism in the awarding of public contracts during the pandemic, the party has written to Simon Case, the cabinet secretary, and the Tory party co-chair Amanda Milling. It comes a day after a court hearing examining how Downing Street awarded a £564,393 research contract without tender, which heard that Dominic Cummings was central to the decision to give the work to a company run by two longstanding associates. Last week, the shadow cabinet office minister, Rachel Reeves, said that in government the party would follow a policy of “insourcing” as a means of ending cronyism, saying Boris Johnson’s government was “rife with conflicts of interest”. Reeves has written to Case, who is also the head of the civil service, to express alarm at “a lack of transparency around government contracts”, pointing to examples such as a “high-priority” channel for suppliers of medical PPE with political connections, where bids were 10 times more likely to be successful. The letter asks Case to provide details of any meetings with companies awarded contracts, and of those present, including ministers, MPs, special advisers, civil servants, Conservative party staff and others. “To restore transparency and public trust, this information is extremely important,” Reeves wrote. In a separate letter to Milling, Angela Rayner, Labour’s deputy leader and party chair, asked the Tories to assist with discovering details of the profit margins enjoyed by companies awarded the 10 biggest Covid-related contracts, “in order to demonstrate to the British people that taxpayers’ money is being spent wisely”. Fears of cronyism were sparked by public money “seemingly handed out to companies with close links to the Conservative party, or companies who have donated money to the Conservative party, with no discernible track record and in many cases a failure to deliver for the public”, Rayner wrote. Labour is also tabling parliamentary questions to Michael Gove, Reeves’s opposite number in government, to seek details about meetings with Tory-linked companies awarded contracts. The party says more than £2bn of taxpayers’ money has been spent on products and services provided by firms with a financial or personal connection to the Conservative party. Contracts highlighted by the party include those awarded to Randox, the testing company that has employed the Conservative MP Owen Paterson as a consultant, and Hanbury, the political consultancy whose founders include the senior Vote Leave figure Paul Stephenson.