Downing Street today published a humiliating “lost” WhatsApp message that Boris Johnson sent a Tory donor begging for more cash to revamp his grace-and-favour flat.

The PM failed to inform his own ethics advisor about the message, which he sent to peer Lord Brownlow in November 2020 as the six-figure makeover spiralled out of control.

The text exchange shows the PM asked Lord Brownlow for “approvals” for the £112,000-plus makeover, moaning the flat above 11 Downing Street was a “bit of a tip” – despite the fact it had a new kitchen in the last decade.

He pressed the donor to provide money, saying he was “keen” to let the designer get on with it. Lord Brownlow replied promising to get on with the job, adding: “It’s only me and I know where the £ will come from”.

The Prime Minister was accused of lying to watchdog Lord Geidt by saying he didn’t know who funded the £112,000-plus makeover until three months later.

Scroll down to read the messages in full.

Lord Geidt, the PM’s advisor on the ministerial code, said the failure to disclose the texts to his probe into the funding of the refurb was “plainly unsatisfactory”, demonstrated “insufficient respect” and presented a “threat to public confidence” in his role.

And while he suggested the texts alone did not undermine his conclusion that Mr Johnson had not broken the ministerial code, he said he would have had more questions for the PM had he know of their existence.

Yet despite voicing “grave concern” he cleared Mr Johnson of wrongdoing – after the PM claimed he forgot about the messages because they were on his old phone.

The Prime Minister blamed a security breach, in which his phone number was left online for more than a decade, for the switch.

He made a “humble and sincere” apology to Lord Geidt.

Lord Geidt said there were “potential and real failures of process in more than one part of the apparatus of government.”

The watchdog also warned he “doubted” he would have concluded “without qualification” that Boris Johnson declared his interests in line with ministerial code, if the texts had been available at the time of his initial probe.

It comes after the Tories were fined £17,800 by the Electoral Commission last month for breaching election law over failures in how the money was declared.

The PM’s wife Carrie oversaw a redecoration in the four-bed living space above 11 Downing Street – traditionally used by PMs as it is bigger and more luxurious than the two-bed flat above No10.

The makeover by designer Lulu Lytle is said to have included £840-a-roll wallpaper, a £9,800 Baby Bear sofa and a £3,000 Lily Drum table.

The lavish refurbishment cost between £112,000 and £141,000. Boris Johnson eventually paid £112,000 of the money himself following a media storm.

But the November 2020 text to Lord Brownlow shows the lengths the PM went to try to avoid footing the bill.

The pair also discussed plans for a ‘Great Exhibition’ like that held by the Victorians, which established the Crystal Palace.

Mr Johnson texted Lord Brownlow on November 29: “I am afraid parts of our flat are still a bit of a tip and am keen to allow Lulu Lytle to get on with it.

“Can I possibly ask her to get in touch with you for approvals?

“Many thanks and all best Boris.

“Ps am on the great exhibition plan Will revert.”

Lord Brownlow replied three hours later: “Afternoon Prime Minister, I hope you’re both well.

“Sorry for the delay I was out for a walk and didn’t have my ‘work’ phone with me.

“Of course, get Lulu to call me and we’ll get it sorted ASAP ! Thanks for thinking about GE2. Best wishes David”

The donor then texted again, adding: “I should have said, as the Trust isn’t set up yet (will be in January) approval is a doddle as it’s only me and I know where the £ will come from.

“So as soon as Lulu calls we can crack on – David.”

The Prime Minister today refused to answer detailed questions, insisting: “I followed the ministerial guidance at all times.”

But Labour deputy leader Angela Rayner said: “It is simply impossible to read these exchanges and conclude that the Prime Minister has not breached these aspects of the Code.

“Once again, by attempting to hide the truth, Boris Johnson undermines his own office.

“This matters because it matters who has influence on our government in a democracy. The British public can’t WhatsApp a wealthy donor to open their wallets on request, and the least they deserve is transparency about who’s bankrolling their Prime Minister.”

SNP Deputy Westminster Leader Kirsten Oswald added: “Boris Johnson’s sleazy Tory government is the most corrupt in decades. If the Prime Minister had a shred of decency or integrity he would have resigned months ago – but he doesn’t.”

Lib Dem Chief Whip Wendy Chamberlain said: “This is just another day in the Number 10 circus act and the latest chapter in the Conservative sleaze scandal.”

In terse letters published today, Lord Geidt – who reportedly considered resigning – admitted: “The episode shook my confidence precisely because potential and real failures of process occurred in more than one part of the apparatus of government.”

He said it was “unwise” for No10 staff not to alert him to Lord Brownlow’s texts once the PM’s aides eventually became aware of them.

“I believe this episode demonstrated insufficient regard or respect for the role of Independent Adviser,” he fumed.

He added: “Had I been aware of the Missing Exchange, I would have had further questions and drawn attention to it in my report.

“More crucially, I doubt whether I would have concluded, without qualification, what is set out in paragraph 33 of my report, that ‘at the point when the Prime Minister became aware, he took steps to make the relevant declaration and to seek advice’.”

In a furious letter to the Prime Minister, Lord Geidt said donor Lord Brownlow was the one in possession of the “missing exchange”.

The donor had offered to furnish the Cabinet Office with the messages, but in an “extraordinary” decision, the Cabinet Office did not accept the offer – or tell Lord Geidt such information had been volunteered.

Yet after the PM’s apology, the ethics chief said he could “conclude the matter” and there was no change to his assessment that the PM did not break the Ministerial Code.

He told Mr Johnson: “I am very grateful to have your apology for these shortcomings and to know of your determination to prevent such a situation from happening again.”

The PM also promised a “specific proposal in January” to strengthen Lord Geidt’s role with the “highest standards of support and attention”.

Lord Geidt, the independent adviser on ministerial interests, issued his initial report in May 2021.

It said the PM had “unwisely” allowed the redecoration to go ahead without considering who would pay the bill.

Mr Johnson assumed a charitable trust that didn’t yet exist would foot the bill for the extensive work, led by Tory donor Lord Brownlow.

But this fell through due to legal concerns about a charity funding the PM’s flat, prompting Lord Brownlow to cough up £112,549,42 through three cheques.

In March the PM then “settled the full amount himself” – effectively paying back Lord Brownlow and the Conservative Party, who’d handled some of the money.

A further £28,647 was spent by the Cabinet Office on Downing Street refurbishment – part of an annual allowance – but it was unclear whether it was for the flat.

Lord Geidt’s original report last May said: “The record shows no evidence of the Prime Minister being aware either of the existence of these invoices or how they were settled.”

The PM’s spokesman said last month that Mr Johnson had “some limited contact” with Lord Brownlow, but “the record shows no evidence that the Prime Minister had been informed by Lord Brownlow that he had personally settled the total costs.”

Asked if the PM lied to the British public, his spokesman replied: “No.”

Asked if the PM lied to Lord Geidt, his spokesman replied: “No.”

This breaking news story is being updated.