Dominic Cummings has admitted he thought Boris Johnson being Prime Minister was “terrible for the country”, but that he and “a few dozen” backers sought to use his premiership to their advantage.

The former de facto chief of staff in No 10 said he had found Mr Johnson to have “hopeless” traits after working with him during the 2016 Brexit referendum, but agreed after he entered Downing Street three years later to assist him.

But Mr Cummings, who left No 10 in the autumn after a power struggle, admitted he was now working to bring an end to Prime Minister’s tenure.

Asked during a BBC interview aired on Tuesday whether he was looking to “hasten” Mr Johnson’s departure from Downing Street, he said: “Certainly. The sooner he goes the better, for sure.”

The least bad option seemed to be, exploit the current situation to try and push certain things through and get the country into a better position

In the hour-long broadcast, Mr Cummings said he had looked to “exploit” the situation the country found itself in after Mr Johnson took power in 2019.

Mr Cummings, asked whether he had agreed to work with Mr Johnson so he could “get him to do what you wanted”, replied: “In part, yes. He didn’t know what he was doing but he did know that he needed help.”

The Vote Leave mastermind added: “I think it is terrible for the country but I keep trying to stress, you’ve got to balance up the different possibilities.

“From a practical matter, all our options were bad, so it was, which is the least bad option? The least bad option seemed to be, exploit the current situation to try and push certain things through and get the country into a better position.”

Asked who was behind the decision to back Mr Johnson on the premise of securing Brexit, he replied: “Me and a network of people – some of us who did the Vote Leave campaign, some of us who did other things. A few dozen maybe.”

During the programme, Mr Cummings made a series of allegations, including:

– The Prime Minister did not take the threat of coronavirus “seriously” in the early stages of the pandemic and that it was a “nonsense” scare story.

– He had to talk Mr Johnson out of going to see the Queen in-person only days before a national lockdown was ordered in March 2020, warning him he could give the monarch Covid-19 and kill her.

– Mr Johnson argued in September as Covid cases were rising that it was mainly older people who were dying of the virus and that he “no longer bought all this NHS overwhelmed stuff”.

– Mr Johnson fell out with his closest aide because he was “fed up with the media portrayal of him being a kind of puppet for the Vote Leave team”.

– He helped broker a deal between Mr Johnson and Cabinet Office minister Michael Gove to become prime minister and chancellor respectively after the Brexit result.

Responding to Mr Cummings’ criticism of Mr Johnson’s handling of the pandemic, Downing Street said the Prime Minister had “taken the necessary action to protect lives and livelihoods, guided by the best scientific advice”.

Another revelation made by Mr Cummings was that he considered a coup against Mr Johnson only “days” after the 2019 poll – during which he had helped him secure one of the largest general election wins in decades – due to fears the Conservative Party leader’s then-girlfriend, Carrie Johnson, was trying to oust Vote Leave personnel.

“Before even mid-January we were having meetings in Number 10 saying it’s clear that Carrie (Johnson) wants rid of all of us,” he said.

“At that point we were already saying by the summer either we’ll all have gone from here or we’ll be in the process of trying to get rid of him and get someone else in as prime minister.”

He said there was a “big argument” after Mrs Johnson, a former Tory head of communications, was looking to appoint and fire people “in ways that I thought were unethical and unprofessional”.

No 10 said political appointments are “entirely made by the Prime Minister”.

The 49-year-old also accused Mr Johnson of not having a plan for office and said he “doesn’t know how to be Prime Minister”, claiming his “only agenda” to be “buy more trains, buy more buses, have more bikes and build the world’s most stupid tunnel to Ireland – that’s it”.