Boris Johnson vows to fight on amid growing wave of resignations

Britain's Boris Johnson defiantly vowed on Wednesday to fight on against growing calls for him to resign as prime minister, but his pledge to keep going was met with scornful laughter at a parliamentary appearance.

Badly wounded by the resignations of a stream of senior colleagues and junior ministers who said he was not fit to govern, Johnson sought to come out fighting at parliament's weekly prime minister's questions session.

"The job of a prime minister in difficult circumstances," is to keep going," Johnson said. "And that's what I'm going to do."

Earlier, he tried to reassert his authority by quickly appointing Nadhim Zahawi, a rising star in the Conservative Party widely credited for the successful rollout of COVID-19 vaccines, as finance minister.

But Johnson's performance encountered a brutal response.

Underlining the tenuous position he is in, some colleagues in his cabinet team of top ministers struggled to contain their laughter as the opposition Labour leader poked fun at his cabinet for being in the "charge of the lightweight brigade".

Three members of Johnson's own party asked whether he would resign.

To one, he replied: "There is a very simple reason why they want me out and that is they know otherwise we are going to get on and deliver our mandate and win another general election."

"Clearly, if there were circumstances in which I felt it was impossible for the government to go on and discharge the mandate that we've been given, or if I felt, for instance, that we were being frustrated in our desire to support the Ukrainian people ... then I would," Johnson said.

Overall, it was a muted performance for a prime minister who has seen his political fortunes tumble from a landslide election victory in 2019 to now, when the resignation of his finance and health ministers opened the floodgates for more junior ministers to quit.

Shortly afterward, his former health minister, Sajid Javid, detailed the scandals, missteps and gaffes that have marked Johnson's tenure so far.

"Treading the tightrope between loyalty and integrity has become impossible in recent months," Javid told a silent parliament, with Johnson listening stony-faced.