Boris Johnson is “desperate” to distance himself from cronyism allegations despite being at the centre of them, Sir Keir Starmer has said.
The Labour leader said it was “increasingly obvious” the prime minister was involved in “sleaze”.
His comments follow the publication by the BBC of texts between Mr Johnson and businessman Sir James Dyson.
Downing Street declined to comment on “speculation” that the PM’s former aide Dominic Cummings was behind the leak.
The government has launched an internal inquiry into who was responsible.
The prime minister’s spokesman said: “We don’t get into detail of processes in terms of these inquiries, but the Cabinet Office is taking that work forward.”
Asked if media reports pointing the finger at Mr Cummings were part of an attempt to distract from lobbying allegations, Sir Keir said: “Boris Johnson is desperate to try to keep this at arm’s length but it’s obvious that he can’t. This is government by WhatsApp.
“They are all at it – whether it’s access to the prime minister, whether it’s the former prime minister accessing ministers and officials, whether it’s the health secretary with shares in companies with the contracts with the NHS. The list just grows and grows…
“Sleaze is back and it’s bigger than it was before.”
Shadow Treasury minister Bridget Phillipson tweeted: “Dominic Cummings is a distraction. Follow the money, not the soap opera.”
On Tuesday the BBC published text messages between Mr Johnson and Sir James, in which the prime minister agreed to “fix” concerns the businessman had over his employees’ tax bills if they moved to the UK to make ventilators at the start of the pandemic.
Mr Johnson said he made “no apology for moving heaven and earth” to ensure there was enough medical equipment to treat coronavirus patients.
He promised to publish all his correspondence with the businessman “shortly”.
Labour has called for an urgent investigation into the prime minister’s conduct by the Liaison Committee of senior MPs.
It said the text messages showed Mr Johnson had offered a “tax break” to a “chum”.
The head of the committee, Conservative MP Sir Bernard Jenkin, turned down the call for an inquiry, saying three other parliamentary committees were already looking at the issues.
He told Radio 4’s Today programme ministers should not be “locked away in ivory towers” with people unable to contact them and should be able to carry out conversations about policy in private, as this would “stifle proper conversation”.
“What’s got to come out of this is obviously a system of managing conflicts of interest, which commands more public confidence, and is more rigorous, but also a balance,” he added.
Mr Cummings has not accepted invitations to respond to the reports and, so far, no evidence of his involvement in the leaks has been produced.
In a statement, the BBC said: “We do not discuss our sources.”
Read from source: https://www.bbc.com/news/uk-politics-56856901