DOWNING Street has tried to back away from an earlier pledge to investigate allegations of Tory MPs being blackmailed into keeping Boris Johnson in power.

On Thursday, the Prime Minister said the claim would “of course” be looked into, although he added he had “seen no evidence” to support it.

This morning, Business Secretary Kwasi Kwarteng also said the claims, if true, would be “completely unacceptable” and ministers “need to the get to the bottom of the matter”.

However within hours, Number 10 started to attach conditions, and said there would only be an investigation “if there was any evidence” in support, despite existing testimony.

The resistance to a potentially damaging new front opening up in the partygate affair comes as Number 10 girds itself for the report by ethics mandarin Sue Gray.

The Times reported Ms Gray now has an email in which Mr Johnson’s private secretary was advised against holding a drinks party in the Number 10 garden on May 20, 2020.

Mr Johnson went on to attend the event for around 25 minutes, but insists he believed it was a work gathering, despite the food and alcohol on display.

Ms Gray’s report into multiple allegations of partying in and around Downing Street while the rest of the country was locked down for the pandemic is expected next Wednesday.

A plot led by so-called Red Wall Tory MPs to oust Mr Johnson faltered earlier this week after Christian Wakeford defected to Labour, inspiring a wave of Tory unity in response.

However if 54 Tory MPs send letters to Sir Graham Brady, the chair of the 1922 committee, they could still trigger a confidence vote in the Prime Minister within days.

The blackmail allegations were aired yesterday by Tory MP William Wragg, who wants Mr Johnson to resign, and who said colleagues had reported being threatened by the whips with the loss of public funds from their constituencies if they turned against Mr Johnson.

Mr Wragg, chairman of the Commons Public Administration and Constitutional Affairs Committee, said that, plus threats to leak embarassing stories to the media, could amount to “blackmail” and urged MPs to report it to the police.

Mr Wakeford, the Bury South MP who defected to Labour on Wednesday, then said he was told that funding for a new school in his constituency would be withheld if he did not vote with the Government over free school meals.

He told BBC North West: “I was threatened that I would not get the school for Radcliffe if I did not vote in one particular way. This is a town that’s not had a high school for the best part of 10 years.”

The Times reported today that MPs who experienced such measures were considering releasing damaging messages and even a recording of the chief whip.

Speaking on Sky News today, Mr Kwarteng said: “As far as the specific allegation about whips withholding funds, I think that’s completely unacceptable.

“Any form of blackmail and intimidation of that kind simply has no place in British politics.

“We need to get to the bottom of the matter. But I find it very unlikely that these allegations are true.”

He said Mr Wakeford’s “very serious” allegation was so far “unsubstantiated”.

He added on BBC Radio 4: “I’m sure it will be investigated if it’s not being so already - after 12 years as an MP I’ve never heard anything like this.

“Having been an MP for 12 years I’ve never heard of anyone making a threat, certainly not to me or to anybody else of that kind, doesn’t mean it’s not true.”

However a spokesman for the Prime Minister later knocked down the idea that the matter would automatically be investigated. 

He said: “We’re not aware of any evidence to support what are clearly serious allegations. If there was any evidence to support it, it would of course be looked at.”

Scottish Tory leader Douglas Ross has said the allegations should be “properly investigated”. Nicola Sturgeon has also said an independent investigation is needed into what she describing as a shocking symptom of the UK Government’s “moral decay”.

Meanwhile, Welsh First Minister Mark Drakeford has said history is catching up with Mr Johnson, and he is not surprised that the PM is now embroiled in partygate. 

“If I’m truthful about it, the Prime Minister is someone who’s been sacked from two previous jobs for not telling the truth,” he said.

“In many ways, I think what you see is his history catching up with him.”

Mr Drakeford said the decision this week to lift all Covid restrictions in England was about distracting the public’s attention from the scandal engulfing Mr Johnson’s administration.

“Everything that goes on in Whitehall and Westminster at the moment for the UK Government is seen exclusively through the lens of, how does this make a difference to the efforts that are being made to shore-up the position of the Prime Minister,” he said.

“This is a Government that at the moment is simply not capable of doing the ordinary business of government in a competent and sensible way because it is overwhelmed by the headlines that surround dreadful events that went on in Downing Street.”