Campaigners have launched legal action against the government over its decision to award a contract to a lobbying and PR firm co-founded by an ally of Dominic Cummings without a competitive tender during the pandemic. A group of lawyers is challenging the Cabinet Office’s decision to give the contract to Hanbury Strategy, which was co-founded by Paul Stephenson, who worked alongside Cummings as the director of communications during the 2016 Vote Leave campaign. In legal papers lodged in the high court, the Good Law Project accused the Cabinet Office, headed by Michael Gove, of apparent bias and favouritism in giving the £580,000 contract to Hanbury. Hanbury was the fourth Tory-linked firm known to have been awarded work during the pandemic under emergency procedures that permit public bodies to give contracts to commercial firms without asking other firms to bid for the work. News of the legal challenge has emerged as the Guardian can report that the Cabinet Office is refusing to disclose any documents under the Freedom of Information Act that would explain what was discussed at an official meeting between Gove and Hanbury on 6 February. The Cabinet Office said disclosure of the documents “would weaken ministers’ ability to discuss controversial and sensitive topics free from premature public scrutiny”. The only information that has been made public by the Cabinet Office about the meeting is that it was about “the Union and devolution”. Hanbury was set up in 2016 by Stephenson and Ameet Gill, David Cameron’s strategy director in Downing Street, and gives political and communications advice to firms. Stephenson was one of the first people to be recruited by Cummings to work on the 2016 Brexit campaign, according to one account. The Cabinet Office hired Hanbury on 16 March, just before the lockdown, to carry out polling to gauge public opinion during the pandemic. The work ended in July. The Good Law Project, a not-for-profit group that aims to use legal methods to expose wrongdoing, is seeking to have the decision to give the contract to Hanbury declared unlawful. The Good Law Project alleged that the government had clearly broken its mandatory obligation to make public the contract within 30 days, as required under official guidelines. The contract only came to light last month through a freedom of information request by the Guardian. Government lawyers are resisting the lawsuit, arguing that the group has no legal right to take legal action as it is not a rival company that has lost out on the opportunity to win the contract. “It is merely a campaigning group with no special interest in the communications sector,” they said. They argued the Good Law Project has initiated six other lawsuits against the government over the awarding of contracts to commercial firms during the pandemic. They “strongly contested” the group’s right to take any of these lawsuits. In another lawsuit, the group is alleging that the Cabinet Office was also biased when it gave a £840,000 contract to a company owned by two long-term associates of Gove and Cummings, without putting the work out for tender. The contract to research public opinion about government policies was given to Public First, a small policy and research company. The Treasury also awarded a three-month £68,000 contract to Hanbury to carry out polling without a competitive tender. A government spokesperson said official guidelines allowed it to award contracts to firms without a competitive tender during national emergencies. The research conducted by Hanbury had helped to make official messages more effective, it added. Hanbury has said its team included some of the UK’s leading experts in polling and data strategy.