Health service representatives have warned of an intense demand on emergency services after the one-day strike by paramedics.
A plea to the public to only call ambulances in life-threatening situations during the industrial action resulted in a significant drop in demand on Wednesday.
But Saffron Cordery, the interim chief executive of NHS Providers, said a “surge in demand” was expected over coming days.
She said: “We know that demand was significantly down.” This was partly due to the public who had “heeded the advice only to call an ambulance if it’s an extreme emergency”.
It was also due to some people not seeking treatment at all. “And I think that’s what we are really worried about. It’s this unseen risk that is sitting out there in communities,” she told Times Radio.
“What we think today, tomorrow, the next few days will bring us, actually, is quite a surge in demand for emergency treatment, people turning up at A&E, potentially calling ambulances because they are in a condition that has significantly deteriorated.”
Thousands of nurses picketed on Tuesday while on Wednesday ambulance staff staged their biggest strike in 30 years. The stoppages came as unions and ministers remained deadlocked over pay negotiations on Wednesday.
Matthew Taylor, the chief executive of the NHS Confederation, said the NHS had “coped as well as could be expected”.
“We saw a quite substantial reduction in 999 calls,” he told BBC Radio 4’s Today programme on Thursday. “The challenge is that demand doesn’t disappear. So, I think we are expecting more intense demand today.
“And that comes on top of a health service which is already finding it very difficult to deal with demand when we have critical incidents in many areas. We are hearing that yesterday there was more demand in primary care so more people phoning 111 and more people being referred for out-of-hospital services.
“So we coped as best we could yesterday. But it’s incredibly important that we recognise that we cannot go on coping with industrial action in the NHS because each time it happens there are direct consequences but also all sorts of knock-on effects.”
He added: “We won’t fully know the consequences of yesterday for a couple of days.”
“We will repeat the call to trade unions and government to step away from rhetoric and step towards negotiation.”
The Daily Telegraph reported that the health secretary, Steve Barclay, was poised to offer an expedited pay deal.
Unions have said they expect NHS workers to be offered a 2% increase next year, based on a letter sent by Barclay to the NHS pay review body. At least 11,509 staff were absent from work across England during strikes by the Royal College of Nursing on Tuesday, and 13,797 appointments and procedures had to be rescheduled, according to NHS England.
Thousands of ambulance workers took individual action on Wednesday, with members of the military stepping in to take their place. The next ambulance strike is due to take place on 28 December.
Workers across several other industries are also due to strike in the run-up to Christmas. On Thursday, strikes were being held by Unite members working for Highlands and Islands airports in Scotland, National Highways workers in London and the south-east and the Driver and Vehicle Standards Agency (DVSA) in the north-west, Yorkshire and Humber and north Wales.
On Friday, the National Highways and DVSA strikes were due to continue, while Royal Mail workers are set to begin a two-day national stoppage. On Christmas Eve, strikes are scheduled by RMT railway workers from 6pm, and London bus workers at Abellio.