The Labour Party has called for an investigation into whether Michael Gove broke the Ministerial Code over an “unlawful” COVID contract given to his “friends”.

It follows a joint investigation by openDemocracy and The Guardian, which revealed the £560,000 deal to hold focus groups on the government’s health messaging was handed to a PR firm, Public First, which is run by close associates of Gove’s.

Earlier this month, the high court ruled that the contract was “unlawful” and “gave rise to apparent bias”, because it was awarded without competitive tender.

One of the firm’s directors, Rachel Wolf, used to be Gove’s adviser and co-authored the 2019 Conservative manifesto. The other director, James Frayne, was also previously hired by Gove – and was a friend of Boris Johnson’s former adviser, Dominic Cummings.

When openDemocracy first revealed the personal links between Gove, Cummings and Public First, the Cabinet Office said it was “nonsense” to suggest this was a factor in the firm being awarded the contract.

At the time, a spokesperson said: “Public First was contracted to undertake this work because of their wealth of experience in the area.”

But Labour’s deputy leader, Angela Rayner, has now sent Gove a series of questions about the contract, saying that statements and evidence heard in court “clearly contradict” earlier claims from the Cabinet Office.

“A court has now ruled that the Cabinet Office was not telling the truth,” she said. “On the basis of this evidence, we clearly cannot trust statements that you or your department make, as a court has ruled, which is why we need an independent investigation in order to establish the truth.”

Gove yesterday failed to attend the Commons to answer questions about the contract, with Rayner later saying he was “too chicken to turn up”. She also accused the Cabinet Office of having “a contempt for the truth and habitual dishonesty”.

Emails released in court show that government officials referred to Public First as one of the companies that “he [Gove] / no10 want to lead” – and this was confirmed “in chat with spads [special advisers]”.

Another message said: “I need to ensure we’re giving him [Gove] what he asked for.”

In a witness statement to the court, Cummings described himself as being the “driving decision-maker” behind awarding the Public First contract. But he claimed: “Obviously I did not request Public First be brought in because they were my friends. I would never do such a thing.”

Justice O’Farrell ruled it was “incumbent on those involved in the appointment of Public First to ensure that there was a clear record of the objective criteria used to select Public First over other research agencies so that they could allay any suspicion of favourable treatment based on personal or professional friendships.”

The £560,000 contract was issued without competitive tender because of the coronavirus emergency, and was meant to cover “urgent communications support”. But it was later extended to cover “qualitative research into EU-exit topics and themes, rebuilding the economy and attitudes to the UK Union”.

The company went on to win more than £1m of public contracts without tender under the emergency COVID provisions.

Reports suggest the government spent up to £600,000 on its failed legal defence, after the case was taken to court by the Good Law Project.

Responding to questions in the Commons yesterday, Conservative minister Julia Lopez said: “I don’t think anyone is standing here suggesting that everything went smoothly during the height of the pandemic. It did not.”

She added: “Everyone involved was acting under immense pressure and the urgency of the crisis did not allow time for reflection.”