The UK government faces growing calls to release details of a VIP fast lane for emergency procurement contracts related to its pandemic response after the health secretary, Matt Hancock, was found to have acted unlawfully.

A high court judge ruled on Friday that the failure to publish multibillion-pound Covid-19 government contracts within the 30-day period required by law breached the “vital public function” of transparency over how “vast quantities” of taxpayers’ money was spent.

Last year, ministers and officials refused to admit which companies were awarded multimillion-pound Covid-19 contracts after being processed in a high-priority channel for firms with political connections.

A report by the National Audit Office said a government unit, set up to procure PPE in a highly unusual departure from standard procurement practice, established the high-priority lane to deal with leads “from government officials, ministers’ offices, MPs and members of the House of Lords, senior NHS staff and other health professionals”.

Almost 500 companies given high priority due to such connections secured contracts to supply PPE with 10 times the success rate of nearly 15,000 companies that were not given enhanced attention.

Labour stepped up its criticism of the government on Saturday, led by deputy leader Angela Rayner who said the government must “come clean” over £2bn in funds awarded to “donors and cronies”, adding: “This is public money, the public has a right to know.”

The shadow chancellor to the Duchy of Lancaster, Rachel Reeves, tweeted: “How much further does this have to go before this government cleans up its contracting? Publish outstanding contracts and details of the VIP fast lane now.”

The shadow health minister, Rosena Allin-Khan, tweeted: “Tory donors were given VIP PPE contracts. The price government paid for PPE increased 1,400%. Many orders were unusable or inadequate, but refunds were not given.”

The Good Law Project (GLP) has called on the government “to publish the names of all the companies who went through the VIP lane, together with who introduced them and, where they were successful, the prices they were paid”.

It has also urged the government to publish PPE contracts “with pricing details visible to enable proper scrutiny” and recover funds from companies who failed to meet their obligations.

Research by the procurement consultancy Tussell had found Hancock’s Department of Health and Social Care (DHSC) had spent about £15bn buying PPE from different companies by the beginning of October, but that only £2.68bn worth of contracts had been published.

Government regulations require all contracts with a value of more than £10,000 to be published and to be sent for publication within 30 days of being awarded.

The Liberal Democrat’s foreign affairs spokesperson, Layla Moran, who supported the GLP in the case, said the ruling should mark the end of the secrecy over the government’s Covid spending.

“Without our judicial review, who knows how many contracts would still remain unpublished,” she said. “Indeed, government only began to rectify the situation after we initiated legal proceedings.”

The DHSC was contacted for comment. On Friday, it said contracts were awarded “at speed” to secure PPE during the pandemic, and that 8bn items were delivered to frontline workers for their protection.

“We fully recognise the importance of transparency in the award of public contracts and continue to publish information about contracts awarded as soon as possible,” the department said.

During the court case, the DHSC’s head of procurement explained the challenges of procuring PPE rapidly during the pandemic and ensuring that contracts were published. The department denied it had any intention not to publish them.

Hancock has not acknowledged the ruling publicly, but tweeted a photo on Saturday morning thanking NHS workers for their service during the pandemic.

A DHSC spokesperson said: “We have been working tirelessly to deliver what is needed to protect our health and social care staff throughout this pandemic, within very short timescales and against a background of unparalleled global demand.

“This has often meant having to award contracts at speed to secure the vital supplies required to protect NHS workers and the public.

“As the 2020 NAO report recognised, all of the NHS providers audited were always able to get what they needed in time thanks to the effort of government, NHS, armed forces, civil servants and industry who delivered over 8bn items of PPE to the frontline at record speed.”