Boris Johnson is standing by housing secretary Robert Jenrick as the embattled minister faces calls to quit over his role in approving a development in east London.
Downing Street said the prime minister still had "full confidence" in Jenrick, but confirmed Johnson had spoken to him about the controversy in recent days.
Jenrick is fighting to keep his job after documents revealed the extent of the contact between himself and multimillionaire Richard Desmond before the cabinet minister signed off on the 1,500-home Westferry Printworks scheme in east London.
The pair exchanged text messages following a meeting at a Conservative Party event in November, and officials in Jenrick's department described him as being "insistent" that the project be given the green light before a new levy added millions to the cost.
Jenrick later had to quash his own approval, conceding that the decision was "unlawful" due to "apparent bias”.
Labour claims the move to approve before Tower Hamlets Council's community infrastructure levy (CIL) came into force would have saved Desmond's Northern and Shell company up to £50 million on the scheme, which was reported to be worth £1 billion.
Business minister Nadhim Zahawi said the fresh documents proved there was no overt influence exerted by ex-Daily Express owner Desmond.
Under pressure to explain why a wealthy businessman could have such access, Zahawi indicated that anybody could deploy similar tactics.
"If people go to a fundraiser in their local area, in Doncaster (for example), for the Conservative Party, they will be sitting next to MPs and other people in their local authorities and can interact with different parts of the authority," he said.
Zahawi stressed that "the access did not buy this billionaire a decision”.
A Labour spokesman said: "Senior Tories say that anyone can get the same access to the government Richard Desmond enjoys – all they have to do is attend swanky Tory fundraisers and hope they get sat next to an MP.
"The 'cash for favours' scandal has laid bare that it's one rule for the Tories and their wealthy friends, another for the rest of us.”
Liberal Democrat housing spokesman Tim Farron added: "The 'defence' of Robert Jenrick is in reality little more than an admission of cash for access.
"It seems the Tory Party's commitment to the 'levelling up' agenda amounts to sleaze and corruption.”
But the PM's official spokesman repeatedly stressed that Johnson believed the case was closed.
"The PM has spoken with the communities secretary," the spokesman said. "The communities secretary gave his account in public and to parliament and published the relevant documentation.
"In light of the account that was given, the PM considers the matter closed.”
Labour leader Sir Keir Starmer told the BBC: "It's now got to the stage where the prime minister's judgement is in issue. He says the matter is closed but it's far from closed.”
The stash of documents and texts, released after pressure from the opposition, showed that multi-millionaire Tory donor Desmond urged Jenrick to approve the east London development scheme so that "Marxists" did not get "doe (sic) for nothing”.
Desmond donated £12,000 to the Tories two weeks after Westferry was approved by Jenrick.