The NHS in Wales is coping with increased pressures on services after junior doctors began a three-day walkout over pay, health bosses have said.

Up to 3,000 junior doctors across Wales started industrial action on Monday morning after refusing a 5% pay offer from the Welsh Government.

NHS Wales said around 30% of planned procedures or operations had been postponed on Monday and 45% of outpatient appointments had to be rescheduled because of the strike.

On an average day there are 1,300 planned operations and on Monday 400 were postponed. There were also on average 14,500 outpatient appointments a day, of which 6,500 were rescheduled.

While 13 of 19 hospitals across Wales were reporting being in level red, which is the busiest level for NHS services.

Judith Paget, chief executive of NHS Wales, said the priority was to ensure services such as A&E, critical care and maternity services could continue during the industrial action.

“But with thousands of junior doctors on strike over those three days there is obviously a significant impact on our NHS services,” she told a Welsh Government press conference.

“Health boards have planned new rotas and consultants and specialist doctors have helped to provide cover.

“The focus is on emergency and life-saving services.

“While some planned treatments scheduled to take place over this three-day period have been postponed and health boards have also not arranged appointments or procedures during this time.

“We will have a fuller, more accurate picture of the disruption by the end of the week.

“But so far, I can tell you that our hospitals have been busy as expected, that they are coping and they’re keeping essential services running.”

The doctors’ trade union, BMA Cymru Wales, said the vote to strike was taken as part of a pay restoration campaign which it said has been eroded by almost a third since 2008/9.

The Welsh junior doctors’ committee made the decision to ballot members in August after being offered a 5% deal by the Welsh Government – below the recommendation of the pay review body.

Health minister Eluned Morgan said a higher pay offer was impossible without additional funding from the UK Government.

“We fully understand the strength of feeling behind the strike action but our funding settlement, which comes largely from the UK Government in the form of a block grant, is simply not sufficient to recognise the demands junior doctors are making,” she told the press conference.

“The offer we’ve made of a 5% increase, which has already been paid into junior doctor pay packages, is equal to that that has been made and accepted by other NHS workers.

“This is at the limits of the finances available to us and whilst we have not been able to meet the recommendations and pay review body this year, during the last financial year we offered a significantly higher sum than was given in England.

“The UK Government has failed to properly fund public services.

“As a result of persistently high inflation Wales’s overall budget is worth £1.3 billion less in real terms than when it was set in 2021.”

Ms Morgan said the UK Government had failed to provide clarity about next year’s financial settlement as a result of NHS pay deals made in England.

“The autumn statement provided some detail but with just a few months of the financial year left we still don’t know the full position regarding consequential funding resulting from the NHS pay increases in England, which were announced nine months ago,” she said.

“We also don’t have any clarity about how the pay offer for NHS consultants in England will be funded.

“This piecemeal approach is severely impacting our ability to plan and illustrates how the current funding arrangements don’t work for devolved governments.

“I want to make it clear that we’re always open to continuing talks with the BMA and NHS Wales employers to find a solution.”

Conciliation service Acas said it was prepared to step in and help mediate the dispute.

Marina Glasgow, chief conciliator, said: “Acas has decades of experience in resolving disputes and our collective conciliation service is impartial, free and independent.

“It is also voluntary, which means we can only hold formal conciliation talks if all the parties in dispute agree to use Acas.”