Multiple NHS trusts across England have declared “critical incidents” amid soaring staff absences caused by Covid-19, with health leaders saying many parts of the service are now “in a state of crisis”. Boris Johnson on Monday ruled out the introduction of new curbs “for now” but said he recognised that the pressure on the NHS and its hospitals, was “going to be considerable in the course of the next couple of weeks, and maybe more”. More than half a dozen trusts have issued alerts over “internal critical incidents” in recent days, it is understood, as concerns mount that some may be unable to deliver vital care to patients. Health leaders said the “rapidly increasing” number of absent NHS staff was piling “very serious” pressure on hospitals already struggling to cope with increasing Covid admissions and “huge wider pressure” on urgent and emergency services. They said pressure was increasingly spreading to hospitals outside London, with those in the north-east and Yorkshire reporting the most rapid growth in Covid patient numbers in recent days. Johnson said there was no question Omicron continued “to surge through the country”, adding it would be folly to think the pandemic was over. A further 157,758 lab-confirmed Covid-19 cases have been recorded in England and Scotland as of 9am on Monday, the government said. However, speaking publicly for the first time this year during a visit to a vaccination centre in Aylesbury, Johnson said the UK remained in a much better position than this time last year thanks to vaccines and stressed Omicron was “plainly milder” than previous variants. NHS chiefs also expressed cautious optimism that after weeks of rising hospitalisations in London – the centre of the Omicron outbreak – the increases may have peaked and are starting to level off. Chris Hopson, the chief executive of NHS Providers, which represents NHS hospital, mental health, community and ambulance services, said: “We were seeing increases in the number of Covid-19 patients in London hospitals go up by 9% a day, 15% a day …  in terms of 27, 28 and 29 December. “Interestingly, in the last two days the increases have only been 1% and 2%, so they’ve dropped pretty significantly, so there’s a hope we might have seen a possible peak and plateau.” Another piece of positive news, he added, was that hospitals were still not admitting large numbers of seriously ill older people with Covid. Hopson said it was striking that hospital bosses were “pointing to the fact” that outbreaks in care homes were not translating into hospital admissions. One of the UK’s biggest care home operators called on the government to lift visiting restrictions after it recorded one Covid death in the last fortnight. Four Seasons Healthcare, which operates 165 care homes, said close to 4,000 residents were living under strict lockdowns because of outbreaks, but Omicron was proving so mild in a well-vaccinated population that limits on seeing family and friends were in “total imbalance” with the risk. Hopson cautioned that the biggest challenge facing many NHS trusts – like many workplaces across the country in the first week of the new year – was mounting staff absences. Covid-related staff shortages are causing havoc in many sectors, with bins in some areas “overflowing” with waste from the festive period and schools scrambling to hire substitute teachers for the start of the new term. Hopson said a number of trusts across the country had declared “internal critical incidents” over the past few days. United Lincolnshire hospitals NHS trust declared a critical incident with “extreme and unprecedented” staff shortages resulting in “compromised care”. Critical incidents are declared by NHS trusts when they believe they may no longer be able to provide a range of critical services. Declaring an incident enables local health chiefs to call for help from staff and other organisations, and creates a formal interim emergency governance structure to make prioritisation decisions at speed, for example redeploying staff or reprioritising services. Joe Harrison, the chief executive of Milton Keynes University hospital, said while his trust was not yet declaring a critical incident, he expected the “very pressured” situation to get worse before it got better. Meanwhile, in Yorkshire, the ambulance service said: “The added challenge of Covid-19-related absence among staff … is having a significant impact on our frontline operations.” In a blog published on Monday, Matthew Taylor, the chief executive of the NHS Confederation, which represents the healthcare system in England, Wales and Northern Ireland, issued a stark warning that many parts of the health service were “currently in a state of crisis”. “In the face of high levels of demand and staff absence some hospitals are having to declare a critical incident,” he wrote. “Some hospitals are making urgent calls to exhausted staff to give up rest days and leave to enable them to sustain core services. Many more hospitals are having to ban visitors to try to reduce the spread of infection.” Taylor also urged politicians “making optimism and complacency a kind of political virility symbol” not to turn Covid policy “into a new terrain for the culture wars”, but instead to focus on the facts and “listen to those trying to cope on the frontline”. Meanwhile, the Royal College of Nursing (RCN) has written to ministers calling for further measures in England amid “confusing and concerning” differences in restrictions across the UK. “Nursing professionals are questioning the level and nature of the variation between governments,” wrote the RCN’s council chair, Carol Popplestone, and its general secretary and chief executive, Pat Cullen. “We therefore ask that, as secretary of state for health and social care, you work with counterparts across government on a more cautious approach for England without further delay.” Parliament will return from its Christmas recess on Wednesday, when the cabinet is set to meet to review the plan B rules. Ministers are expected to keep restrictions – including mask wearing, Covid passports and home working – as they are. On Monday, Johnson rejected the idea that England’s relatively limited Covid restrictions amounted to a gamble. “The way forward for the country as a whole is to continue with the path that we’re on,” he said. “We’ll keep everything under review. But the mixture of things that we’re doing at the moment is, I think, the right one.”