Care homes are faced with the ultimatum of closing or breaking the law due to the Government's 'no jab, no job' policy, it was claimed today.
Unions and care bosses have warned of a staffing exodus due to the requirement for carers to be vaccinated with two doses by November 11.
Today is the last day for tens of thousands of care home workers who are yet to get their first injection, due to the eight-week gap between doses.
Of the 470,000 care home workers who look after elderly residents in England, 92 per cent had their first dose as of September 5, while 84 per cent are fully-jabbed.
The GMB trade union estimate 70,000 staff who look after elderly residents may not be immunised in time for the November 11 deadline.
Martin Green, chief executive of the country's biggest provider Care England, said homes could be forced to shut, break the law or offer substandard care.
He told BBC Radio 4's Today programme: 'We all accept we want as many people as possible to be vaccinated.
'But I do feel the Government has gone forward with the social care compulsion without understanding the implications, without having a thought-out plan on how they are going to deal with staff shortages.
'Care homes are now in a difficult position, facing the reality of do they have enough staff to maintain safety and quality of care?
'They are in the position of either having to transgress the law or expose people they support to levels of staffing that are not going to deliver the safety you're required to.
'There's the inevitability that in some areas, if you can't get the staff, then there will be care homes that close.'
With less than 24 hours before the deadline for first vaccines, the Government announced a temporary self-certification process for medical exemptions.
It will allow carers to exempt themselves without oversight from a doctor, in a move which has been described as a 'loophole'.
Those who do not need to be vaccinated include people with learning disabilities or autism who find vaccination distressing because of their condition.
Also exempt are people with a severe allergy to the vaccines and those who had adverse reactions to their first dose.
Pregnant care home workers and people with short-term medical conditions will also be able to apply for a 'time-limited exemption', which expires in 12 weeks.
Providers said it could be misused by employees who are not prepared to get jabbed and wish to stay in work for longer, and that it kicks the can down the road.
GMB said the Government had 'fudged it' at the eleventh hour.
Mike Padgham, who runs Saint Cecilia's Care Group in Scarborough, said four of his 164 care staff do not want to get vaccinated, one of whom is medically exempt.
He is calling for the Government to postpone the mandatory vaccination deadline or rethink it entirely, allowing carers to work wearing enhanced PPE and after taking daily tests.
In a letter to be sent to Health Secretary Sajid Javid he wrote: 'I cannot redeploy them, as I have nowhere to redeploy them to.
'Even if I did, I would find it extremely hard to find four care workers to replace them in the teeth of the worst staffing crisis in the history of social care provision.
'Am I to sack them or send them home and leave myself four team members down? If I do sack them, do I leave myself open to four industrial tribunals?
'Whatever I do, I run the risk of contravening Care Quality Commission (CQC) regulations and being prevented from operating as a provider.'
The Government has said the temporary system will ensure those with medical exemptions can continue working.