The prime minister is facing yet another wave of public fury after it was reported he attended a surprise birthday party for himself back in June 2020, with up to 30 people, allegedly in breach of the Covid rules in place at the time.
Emails leaked this week have also suggested that – despite his previous denials – Johnson did actually authorise the evacuation of Afghan animals amid the Taliban takeover last August, meaning they took priority over people.
Both of these new allegations led to Stewart’s appearance on ITV’s Good Morning Britain, where he said: “There’s huge evidence, Boris Johnson lies all the time, you can document hundreds of lies so I don’t think we’re waiting for the Sue Gray report to find out whether he lies.
“He lies to his wife, he lies to his employers, he lies to his colleagues, he lies to Parliament.
“And often he does it in different ways, sometimes he does it by pretending to be ignorant, sometimes he does it with a joke, sometimes he does it by ignoring the question.
“He’s probably the best liar we’ve ever had as a prime minister. He knows a hundred different ways to lie.”
As the former international development secretary under Theresa May, Stewart put himself forward to become the next leader of the Tory party but was unsuccessful.
He then resigned from the Conservative Party a few months later and said he would stand down as an MP at the next general election, in December 2019.
Stewart recalled his unsuccessful campaign to be Tory leader while speaking to GMB, and said he would tell voters on doorsteps not to support Johnson because “he’s completely incapable of focusing on detail, that he will be a terrible prime minister”.
However, Stewart added: “The answer was always, ‘yes, but he can win, he’s very popular’.”
He continued: “And I think the time has come in British politics to reconsider that and accept that maybe there are things that matter apart from your ability to win elections.
“And one of those things is can you run the country well.
“Maybe people should vote for politicians who might not get such huge majorities but can actually do a good job of running things.
“Lying is a very, very bad thing in a leader because you can’t get the civil service or anyone to get behind your policies.”
The Metropolitan Police also announced it was launching an investigation into a “number” of the same parties.