Newly appointed health secretary Sajid Javid has said his immediate priority is ending the coronavirus pandemic, as doctors warned he faces a "baptism of fire".
Paying tribute to his predecessor Matt Hancock, who quit after being caught breaking social-distancing rules by kissing an aide, the cabinet minister said he knows the role carries "huge responsibility" and vowed to do everything he can to deliver for the people.
His return to cabinet followed the resignation of Mr Hancock on Saturday after the leaking of video footage showing the then health secretary in a clinch with married Gina Coladangelo last month, in breach of COVID-19 restrictions.
Mr Javid, a former chancellor and home secretary, said: "Matt Hancock worked incredibly hard. He achieved a lot and I'm sure he will have more to offer in public life. "
He added: "I was honoured to take up this position. I also know that it comes with huge responsibility and I will do everything I can to make sure I deliver for the people of this great country.
"We are still in a pandemic and I want to see that come to an end as soon as possible and that will be my most immediate priority to see that we can return to normal as soon and a quickly as possible."
But in taking up the prominent position, Mr Javid faces a burgeoning and urgent in-tray, having to contend not only with the COVID-19 crisis, but also huge patient waiting lists, continuing demands for a social care plan and a fight over NHS pay.
Speaking to Sky News' Trevor Phillips On Sunday programme Dr Chaand Nagpaul, the chair of the British Medical Association (BMA), said his members were "feeling absolutely exhausted" as a result of the pandemic and highlighted tens of thousands of unfilled NHS vacancies.
Dr Nagpaul added: "This comes at a time when the new health secretary was going to see a baptism of fire, he won't have the luxury of a phased handover, he'll have to make every day count."
He went on: "Sajid Javid has a huge and urgent task ahead.
"He must ensure completing the roll-out of the adult vaccination programme at rapid pace to control spiralling infection rates.
"He must also put forward a credible plan to tackle a backlog of care of unprecedented scale whilst at the same time rebuilding the trust of doctors and the wider healthcare workforce."
Branding Mr Javid the "architect of austerity", Labour's shadow health secretary Jonathan Ashworth said his appointment was like "putting the fox in charge of the chicken coop".
He argued the NHS had entered the coronavirus crisis "on the back of 10 years of underfunding" and "cutbacks".
Mr Ashworth told the BBC: "Sajid Javid was responsible for that. He was a Treasury minister. He was a leading advocate for, indeed an architect of the austerity that has afflicted the NHS these last 10 years, which has weakened it.
"In many ways making him Health Secretary, given his record as an architect of austerity, it's a bit like putting the fox in charge of the chicken coop."
But Mr Javid's appointment was welcomed by former Labour health secretary Alan Johnson, who highlighted his principled stand against the PM's then chief aide Dominic Cummings.
Mr Javid abruptly quit the cabinet last year after being told to sack all his advisers if he wanted to keep his job.
Mr Johnson said: "He is a good appointment by the way, I think in a cabinet of sycophants, which has been one of the problems, he stands out because he refused to accept the outrageous demands placed upon him by the prime minister and Dominic Cummings and gave up his job as chancellor on an issue of principle, and I think that stands him in good stead."