BORIS Johnson is the worst Prime Minister the UK has had in more than half a century “by a country mile”, the former speaker of the House of Commons has said.

John Bercow, who served as the Commons speaker for a decade before standing down ahead of the 2019 General Election, made the comments on Good Morning Britain on Friday.

The former Tory MP - who has now joined the Labour Party - told GMB that Johnson was widely regarded “as a serial dissembler, as an habitual liar, as somebody who has made his career through ducking and dodging and diving and dissembling and deceiving people”.

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He said that the Prime Minister’s behaviour was “incredibly serious and enormously damaging” not just to himself but to the reputations of “everybody involved in politics and on the House of Commons in particular”.

Bercow added: “I'm sorry to say it, but I've known 12 prime ministers in my lifetime, and by a country mile Boris Johnson is the worst.

“His natural instinct is not to be open, not to be transparent, not to be accountable, but narcissistically to think, what suits me? How can I extricate myself from this awkward situation? By what means can I arrogate blame somewhere else?

“This is way below the standard that the British public are entitled to expect.”

Bercow, who was born in January 1963, has actually lived through the tenure of 13 prime ministers.

Speaking on GMB, the former speaker also addressed claims that media should “focus on the big issues rather than wallpaper or the cost of a flat” in the wake of news that Johnson may have lied to his own standards adviser over the affair.

Bercow said: “I suppose the answer to that is this. If there isn't a basic level of trust in the most senior minister in the government, it's very difficult to operate a democratic polity at all. That's the problem.

“This guy stinks in the nostrils of decent people.”

Bercow was not awarded a peerage after he stepped down as speaker contrary to tradition. The move from the Tory government was widely seen as retribution for his anti-Brexit stance.