The UK government is expected to announce mandatory Covid-19 vaccines for frontline NHS staff in England, with a deadline of next spring for both doses.
The UK's department of health said it was not commenting on speculation around the timing of the announcement, which the BBC said would be later on Tuesday.
However, NHS officials said they expected the move to happen, which would affect the thousands of unvaccinated staff working in the health service.
Care home workers in England have already been told they must be fully vaccinated by the deadline of this Thursday.
NHS Providers chief executive, Chris Hopson, said that if mandatory vaccination for NHS staff is approached in the right way it could actually result in a rise in the take-up of jabs.
He told BBC Radio 4’s Today programme: “If you look at other nations that have done this, there is no doubt that if you do it carefully, at the point when you announce the fact that you are going to have mandatory vaccinations in the sector, it does provide quite a useful opportunity to then have those kind of further conversations.
“So if we get it right, actually, it could be quite a useful spur in some senses to drive the take-up up, but the bit that we just need to be careful of, as I said, is avoiding scapegoating people.”
Mr Hopson warned that the NHS and the social care sector losing “significant numbers of staff” would be a “real problem”.
He said: “The problem for both social care and the NHS is we run these systems incredibly hot on very, very fine margins.
“Both of us have got around 90 to 100,000 vacancies.
“We are completely reliant on our staff to … work extra shifts in order to do the work that needs to be done.
“So losing significant numbers of staff, particularly given the pressure that both of the systems are under at the moment, is a real, real problem.
“And that’s why we’re very clear with the government they need to help us manage this risk.”
British justice secretary and deputy prime minister Dominic Raab refused to comment on the reports.
He told BBC Breakfast: “I don’t comment on leaked reports about what the government may or may not do, and that’s just not the professional thing for a minister to do.
“Obviously, we set out our announcements on this in the usual way.
“I think it’s right to say that we’ve been very mindful of encouraging greater take-up – or maximum take-up if you like – of the vaccination and the boosters to go with it, but not just across the country at large, but particularly in vulnerable settings, like care homes and in the NHS.”