Boris Johnson said he makes “no apology for moving heaven and earth” to get ventilators during the pandemic, amid a row over lobbying by Sir James Dyson.
In text messages seen by the BBC, the prime minister promised to “fix” tax changes Sir James wanted.
Mr Johnson said any PM would have done the same in the circumstances, to secure ventilator supplies.
But Labour leader Sir Keir Starmer said it was part of a pattern of government “sleaze” centred on the prime minister.
Sir James wanted to ensure that Dyson workers returning to the UK to help with the pandemic response were not penalised by the tax system.
The Labour leader and the prime minister traded verbal blows at Prime Minister’s Questions, with Sir Keir claiming it was “one rule for those who have the prime minister’s phone number and another for everybody else”.
Mr Johnson insisted he had done the “right thing”, telling Sir Keir: “I make absolutely no apology at all for shifting heaven and earth and doing everything I possibly could, as I think any prime minister would in those circumstances, to secure ventilators for the people of this country.
“And to save lives and to roll out a ventilator procurement which the Labour-controlled Public Accounts Committee themselves said was a benchmark for procurement.”
Sir Keir Starmer compared the way Mr Johnson responded to Sir James’ concerns with the government’s treatment of steelworkers, nurses and three million self-employed people who have been left out of coronavirus support schemes.
He claimed there is a “pattern to this government”.
“Every day there are new allegations about this Conservative government: dodgy PPE deals; tax breaks for their mates; the health secretary owns shares in a company delivering NHS services.
“Sleaze, sleaze, sleaze, and it’s all on his watch.
“With this scandal now firmly centred on him, how on earth does he expect people to believe that he is the person to clean this mess up?”
Mr Johnson took a swipe at Sir Keir, telling MPs: “Captain Hindsight snipes continually from the sidelines; this government gets on with delivering on the people’s priorities.”
I understand Number 11 – the Chancellor’s team – were uneasy about what Sir James Dyson was asking for in his approach to them, and it’s suggested they had quite deliberately not responded to his firm’s requests before Sir James himself then texted the PM directly about the tax issue.
I’m told Chancellor Rishi Sunak did not and has never had any personal contact with Sir James.
When it comes to publication of texts, the Treasury set a precedent a few weeks ago, when they published Mr Sunak’s texts to David Cameron about Greensill.
At PMQs, the prime minister said he would “share all the details with the House”.
But one of the big issues with rules about how ministers are meant to behave is the proliferation of politics being done by text and WhatsApp.
Whatever happened in the case between Boris Johnson and Sir James Dyson, the rules contained in the ministerial code don’t really cover the reality of how people communicate now.
SNP Westminster leader Ian Blackford called on Mr Johnson to reveal “how many more Covid contracts he personally fixed” and publish all personal exchanges on these contracts.
The prime minister said: “There’s absolutely nothing to conceal about this and I am happy to share all the details with the House, as indeed I have shared them with my officials immediately.”
When coronavirus hit the UK in March 2020, the government put out a call to businesses to take part in a “national effort” to increase the number of ventilators in the country.
At the time, the Department of Health feared the NHS could need as many as 20,000 additional ventilators on top of the 5,000 it had – along with an existing 900 to treat children.
The prime minister is understood to have called Sir James on 13 March and asked him to participate.
Dyson answered the call and said it spent £20m on developing its own design – though subsequently the company was not called upon to provide ventilators to the NHS.
But the BBC has discovered that Sir James also raised his concerns with the Treasury, and later the prime minister, about rules that could see staff brought into the UK for the project needing to pay tax.
In the text exchanges seen by the BBC, the PM messaged Sir James saying: “[Chancellor] Rishi [Sunak] says it is fixed!! We need you here.”
When the businessman sought further reassurance for the tax status of the firm and “senior individuals”, the prime minister replied: “I am First Lord of the Treasury and you can take it that we are backing you to do what you need.”
Two weeks later, Mr Sunak told a group of MPs that the tax status of people who came to the UK to provide specific help during the pandemic would not be affected.
Sir James said he was “hugely proud” of his firm’s response in “the midst of a national emergency”, and that he would “do the same again if asked”.
He told the BBC: “When the prime minister rang me to ask Dyson to urgently build ventilators, of course, I said yes.
“Our ventilator cost Dyson £20m, freely given to the national cause, and it is absurd to suggest that the urgent correspondence was anything other than seeking compliance with rules, as 450 Dyson people – in UK and Singapore – worked around the clock, seven days a week to build potentially life-saving equipment at a time of dire need.
“Mercifully, they were not required as medical understanding of the virus evolved. Neither Weybourne (Dyson’s holding company) nor Dyson received any benefit from the project; indeed commercial projects were delayed, and Dyson voluntarily covered the £20 million of development costs.”
Sir James also said his company had not claimed “one penny” from governments in any jurisdiction in relation to Covid.