Michael Gove has told the Covid inquiry it was “ludicrous” to suggest he tried to force through a deal for a new ventilator made by the electronics giant Dyson without proper safety checks.

Emails show a senior official at the health watchdog warned that the former cabinet office minister was trying to “circumvent the regulatory process” in March 2020.

Messages between staff at the Medicines and Healthcare products Regulatory Agency (MHRA) said Mr Gove did not “appreciate the level of risk involved” and was working to a “totally unrealistic” timescale.

A provisional order for 10,000 machines was placed at the time, but the deal was scrapped after Dyson failed to win regulatory approval.

No public money was spent on the prototype.

Dyson said it never intended to make a profit from the venture and wrote off around £20m in research and development costs.

In March 2020, as Covid was spreading across northern Italy, there was a frantic attempt by health authorities to get hold of ventilators to help patients breathe.

The NHS had between 6,000 and 8,000 in stock but modelling suggested it needed 30,000 by the end of June and 90,000 by November to cope with a predicted influx of patients.

On 16 March 2020, the government launched the ‘Ventilator Challenge’ – a drive to encourage domestic UK suppliers to develop new machines or modify existing designs.

The project was overseen by cabinet office officials and involved the MHRA, which helped draw up initial specifications and squeezed an approval process that would usually take 18-24 months into just weeks.

A number of major companies were involved, including the carmakers Ford and McLaren, and the electronics giant Dyson.

At the time, the company’s founder Sir James Dyson held a number of telephone conversations with government officials, including the then Prime Minister Boris Johnson.

The Covid inquiry was shown WhatsApp messages then sent between ministers and government advisers suggesting Sir James was concerned about the pace of project.

On 20 March 2020, Mr Johnson wrote that “Dyson [was] freaking” and called for “Action this day”.

Minutes later ex health secretary Matt Hancock replied, “I have also received the same. I will talk to Dyson and Michael [Gove] and sort it.”

Asked about the deal at the inquiry, the government’s then chief commercial officer, Sir Gareth Rhys Williams, said it was the only example he could recall in the pandemic where he was asked to put a contract in place “against commercial guidance”.

Five days later, on 25 March, Boris Johnson wrote another WhatsApp message to the same group saying that: “Dyson has a ventilator ready to go… It’s safe, effective and loses less oxygen. Rhys Williams has blocked it under the misapprehension that oxygen passes through the motor. That is total b****cks.”

He accused officials of “fiddling while Rome burns” and added: “Sorry but I’m on a mission. Dyson knows what he’s doing and won’t risk his global brand reputation delivering dodgy ventilators.”

Sir Gareth said, at that point, the Dyson prototype pushed air from a fan directly into the lungs of patients, something that could cause safety concerns.

The Dyson team did subsequently “fix” that part of the design, he added.

Later on 25 March, Sir Gareth wrote to Sir John Manzoni, a top civil servant in the cabinet office, saying that Michael Gove was “INSISTENT we place an order with Dyson… contingent on passing clinical and passing MHRA approvals.”

A provisional £100,000 order was then placed for the Dyson prototypes, and an email from Michael Gove’s private office set out a number of actions that needed be taken quickly including: “The MHRA and Sir Gareth Rhys Williams to ensure by the end of Friday, [that] the Dyson product has been tested and approved by MHRA… [and] the final product has started to be manufactured.”

The following day Graeme Tunbridge, the director of devices for the MHRA, wrote to colleagues warning that Michael Gove was “keen to press forward with Dyson’s proposal to a timescale that is totally unrealistic.”

He added that Mr Gove “did not appreciate the level of risk involved in the manufacture and use of ventilators” and “wanted to circumvent the expedited regulatory process that has been put in place”.

“MHRA are doing everything we can to support this but absolutely will not cut any corners when it comes to the issues of critical patient safety,” he wrote.

Giving evidence to the inquiry, Mr Gove denied he had tried to pressure the MHRA in any way, or that the focus on Dyson meant resources could not be devoted to bids from other companies.

“Just imagine the situation, if you will, a minister – Matt Hancock, I, Boris Johnson – says we want to have a potentially lethal machine in hospitals deliberately so that we can meet an arbitrary deadline. It’s inconceivable,” he said.

The former minister said that the Dyson prototype ultimately “did not get through testing” and “whenever confronted with brute facts about safety or otherwise, I would always accept them.”

He denied that his private office was instructing the regulator to approve the device saying the language used was simply “shorthand for ‘we would hope that it had been tested and if tested satisfactorily [then] approved by the MHRA to that timescale”.

In the end the government said the Ventilator Challenge helped scale up the production of three existing models, and approved one new design by the medical devices firm Penlon.

In total, an extra 14,000 devices were delivered over three months, fewer than the government originally planned for as doctors identified other ways of treating the most severe Covid cases.

In a statement, Dyson said it never had any intention of manufacturing Covid ventilators for profit.

“Far from receiving any commercial benefit, there was significant commercial cost to Dyson which diverted 450 engineers away from commercial projects,” said a company spokesperson.

“Uniquely amongst the many businesses involved, [Sir] James Dyson did not seek payment for any of the £20m the company spent on the project – rather this was its contribution to the national effort to save lives.”