Boris Johnson has rejected claims that he is suffering from the aftereffects of catching Covid-19, branding them "seditious propaganda".
The prime minister claimed that the suggestions were invented by enemies of the government's political programme and said the observations about his health were "nonsense".
Observers have suggested that the prime minister's sometimes less-than-energetic deneamour are down to the effects of the illness, which saw him hospitalised. He has previously dismissed the claims as "balderdash".
"I've read a lot of nonsense recently about how my own bout of Covid has somehow robbed me of my mojo!" he said during a speech to the Conservatives' online annal conference, broadcast over the internet.
"Of course, this is self-evident drivel, the kind of seditious propaganda that you'd expect of people who don't want this government to succeed, who wanted to stop us delivering Brexit and all our other manifesto pledges and I can tell you that no power on earth was or is going to do that."
Mr Johnson added: "I could refute these critics of my athletic abilities in any way they want. Arm-wrestling, leg-wrestling, Cumberland wrestling, sprint-off, you name it."
The PM's low-energy performances in the House of Commons and particularly during PMQs have raised eyebrows, given his previously bombastic demeanour.
He has previously been forced to dismiss claims that he will quit the job because of the effects of the illness.
The prime minister added that the reason he had had "such a nasty experience" with coronavirus was because he was "too fat".
"I've since lost 26lbs and you can imagine that in bags of sugar," he said.
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