Nursing and midwifery leaders have urged Sajid Javid to delay the introduction of compulsory Covid jabs for NHS staff and said the controversial policy amounted to “self-sabotage”.

The plea from the Royal College of Nursing (RCN) and Royal College of Midwives (RCM) comes as NHS trusts in England prepare to start sending out dismissal letters from 3 February to any member of staff who has not had their first dose of a vaccine by then.

They fear that the exodus of frontline personnel that mandatory vaccination is likely to trigger will make it even harder for NHS care providers to maintain normal care, given it would happen just as the service is grappling with record levels of staff sickness closely linked to the Omicron variant.

The government’s own risk assessment of mandatory jabs published last November estimated that it could lead to the loss of 73,000 staff in a service that in England already has 93,000 vacancies. NHS bosses recently warned that that could make it unsafe and unviable to run entire units of hospitals, especially maternity units.

“We are calling on the government to recognise this risk and delay a move, which by its own calculations looks set to backfire,” said Pat Cullen, the RCN’s general secretary and chief executive. “To dismiss valued nursing staff during this crisis would be an act of self-sabotage.”

Cullen advised ministers to extend the deadline for staff to have two doses of vaccine, which is currently 31 March, so that trusts have more time to continue their efforts to persuade the still-unvaccinated to get jabbed, which has helped boost the overall immunisation rate in the NHS.

“Encouraging people to get vaccinated is the best way to boost vaccine take-up. Nursing staff, who are well-placed to understand people’s concerns and are highly trusted by them, have led the Covid-19 vaccination programme and have a key role to play in addressing any concerns people may have about being vaccinated.”

Gill Walton, the chief executive of the RCM, warned Javid that his insistence on mandatory vaccination has “opened a Pandora’s box of unforeseen consequences”.

She said: “I appeal to the health secretary to reconsider his decision and to delay the implementation. Throughout the pandemic, maternity staff have fought to keep services open and to provide the best care to women and families. It has been unrelenting and so it’s no surprise that staff absence is currently at its highest in the pandemic so far.

“Moving forward with mandatory vaccination could only see staffing levels fall further. The government has opened a Pandora’s box of unforeseen consequences – but there is an opportunity now to close it. We are urging Sajid Javid to do just that,” Walton added.

“Levels of vaccination in the NHS are high and rising and we should be using discussion, persuasion and education to increase vaccination among NHS staff, not the hammer blow of mandating it.”

Significantly, the NHS Confederation, which represents hospital trusts in England, made clear it believed that the policy is being introduced at undue haste and would deepen already major staffing problems.

“NHS leaders support the requirement that staff who are in regular contact with patients be vaccinated against Covid-19”, said Danny Mortimer, its deputy chief executive.

“Both the risks and consequences of a mandatory approach were highlighted by leaders at the time of consultation, and they would have preferred to have had longer to meet these requirements.

“As the deadline approaches some frontline staff will have to leave their present roles if they continue to decline to be vaccinated. This will reduce frontline NHS staff numbers even further and lead to more gaps in capacity at a time of intense pressure and patient demand”, he added.

However, the Department of Health and Social Care defended the policy. A spokesperson said: “NHS and care staff do amazing work and we are thankful to those who have chosen to get the vaccine.

“Health and social care workers are responsible for looking after some of the most vulnerable people in society, many of whom are more likely to suffer serious health consequences if exposed to the virus.

“This is about patient safety, and ensuring people in hospital or care have as much protection as possible. Vaccinations remain our best defence against Covid-19.”