Tens of thousands of <a href="https://www.thenationalnews.com/tags/nurses" target="_blank">nurses</a> and ambulance staff in <a href="https://www.thenationalnews.com/tags/england/" target="_blank">England</a> have walked out in support of <a href="https://www.thenationalnews.com/tags/salaries" target="_blank">pay</a> claims, as <a href="https://www.thenationalnews.com/tags/nhs/" target="_blank">National Health Service</a> leaders warned of the “worst day of disruption yet” on Monday. The <a href="https://www.thenationalnews.com/tags/strike" target="_blank">strike</a> is believed to be the biggest in the history of the NHS and the first time the two groups have walked off on the same day during a wave of disputes engulfing public services. The public was urged by NHS providers to use emergency services “wisely” as it issued a warning that the whole service was approaching a “crunch point”. The Royal College of Nursing, which is staging a two-day strike, has said it is calling out twice as many of its members than it did during previous protest actions in December and January. “Everyone can see the resilience of our nursing staff, these brilliant people that are standing on the picket lines today, losing another day's pay,” said Pat Cullen, general secretary of the Royal College of Nursing, at a picket line outside St Mary's Hospital in Paddington on Monday. “They are saying patients have had enough, they have had enough. They're not willing to continue to see their NHS managing every day within a crisis. “They're trying to bring their NHS back from the brink and they will continue to do this for as long as this government takes to listen to them.” Ambulance crews and call handlers will return to work on Tuesday but are then due to walk out again on Friday. Unions in Wales largely suspended similar action after the Welsh government came forward on Friday with an improved pay offer. “I think it's going to be a hugely disrupted day across the NHS, it's going to be incredibly challenging,” Saffron Cordery, deputy chief executive of NHS Providers, which represents NHS trusts, told Sky News on Monday “With both nurses and ambulance staff out on strike today, and nurses again tomorrow — and we've got physiotherapist later in the week and some ambulance staff again on Friday — we're planning for an incredibly disrupted week. “What we previously had with industrial action has been, for example, community nursing staff being able to plug the gaps left when ambulance staff are out on strike, but obviously with nurses and ambulances out today, that's going to be incredibly difficult.” NHS Providers chief executive Sir Julian Hartley said they understood why so many of their staff had reached a “tipping point”, as he urged ministers to sit down with unions to negotiate a settlement. Sir Julian said 88,000 appointments had been already been cancelled as a result of the current strike, hitting patients hard. “We’re facing a crunch point. Monday’s co-ordinated walkout by nurses and ambulance workers could see the worst disruption yet for the NHS,” he said. “We face a very real risk that tens of thousands more patients will have their care disrupted in the coming days by this double-whammy of strikes, especially as they’re coming right after a weekend when we know demand for care tends to build up.” Sir Julian said NHS leaders would do everything possible to ensure safe care and minimise disruption for patients, and called on the public to think carefully before seeking to gain access to services. “It’s vital that in the event of an emergency, people continue to call 999,” he said. “But given the severe disruption we’re expecting, we’re asking the public to use services wisely and to think about whether other health issues could be more appropriately dealt with via the NHS 111 website, community pharmacists or their GP.” Maria Caulfield, Minister of Mental Health and Women's Health Strategy, sympathised with striking nurses but said “inflation-busting pay rises” could not be afforded. Speaking to GB News, the Conservative MP and nurse said: “I'm an RCN member myself, so I sit in both camps, if you like. “Absolutely, I have a lot of sympathy. But we also have a responsibility to the taxpayer and we've followed an independent process with the pay review body that unions signed up to and were very happy with the settlement last year. “And it is difficult for us now. If we are to give a pay [rise] to nurses, we would have to look at teachers, ambulance drivers. “We just can't afford inflation-busting pay rises that the unions are currently demanding.” Health Minister Steve Barclay repeated his plea for the unions to call off their strike as he insisted the government could not give in to above-inflation pay claims. “The Governor of the Bank of England warned if we try to beat inflation with high pay rises, it will only get worse and people would not be better off,” Mr Barclay said. “I have held constructive talks with the trade unions on pay and affordability and continue to urge them to call off the strikes.” However, Unite general secretary Sharon Graham said Mr Barclay was “not telling the truth” as neither he nor Prime Minister <a href="https://www.thenationalnews.com/tags/rishi-sunak/" target="_blank">Rishi Sunak</a> had been prepared to discuss pay. “To me, that is an abdication of responsibility [as] the dispute is about pay,” Ms Graham told the BBC. “So, how can they say they are in talks?” RCN's England director Patricia Marquis appealed to Mr Sunak to “come to the table” for pay talks and avert more strike action.