The Royal College of Nursing could denote a caller question of strikes if Health Secretary Steve Barclay does not hold to reopen wage negotiations.
Speaking connected the BBC's Question Time, the union's person Pat Cullen said if the authorities continued to garbage to "get successful a country and talk" past the quality could escalate successful the caller year.
The UK authorities says the union's demands are unaffordable.
Nurses are already readying to onslaught connected Tuesday.
Tens of thousands of nurses took concern enactment crossed England, Wales and Northern Ireland connected Thursday, with tens of thousands of diligent appointments cancelled oregon postponed.
Union sources person told the BBC that if determination is nary determination to reopen wage talks, past caller onslaught dates volition beryllium announced earlier Christmas with a bid of walkouts apt successful January.
The level of disruption could besides increase, with nurses striking crossed much NHS trusts successful England and for longer periods of clip - possibly implicit 2 consecutive days. Industrial enactment is besides taking spot successful Wales and Northern Ireland.
The NHS Confederation, which represents hospitals, has urged ministers to enactment to debar strikes successful the caller twelvemonth which it said could beryllium "more severe" and coordinated with different wellness unions.
The authorities said the nurses' demands for a 19% wage emergence are unaffordable and it has followed the proposal of an autarkic wage reappraisal assemblage successful mounting wages.
Nurses got an other 3% past twelvemonth aft the pandemic and different emergence recommended by a wage reappraisal body.
Speaking extracurricular a infirmary successful London connected Thursday, the UK wellness caput said the authorities was "hugely grateful" to nurses but the 19% wage emergence they wanted was "not affordable fixed the galore different economical pressures that we face".
Mr Barclay said three-quarters of trusts had not gone connected onslaught that time and galore nurses had continued moving successful areas excluded from the onslaught due to the fact that of the hazard to life.
Under onslaught rules, exigency attraction indispensable inactive beryllium provided during action, for illustration successful intensive attraction and A&E, and urgent crab attraction and dialysis should tally arsenic mean - which means the biggest interaction volition person been connected regular services. These see planned genu and hep replacements and out-patient appointments.
Rebecca, a caregiver striking extracurricular St Thomas' Hospital successful London connected Thursday, said her occupation was "too tiring, it's excessively much, it's conscionable not harmless for either the unit oregon the patients to proceed the mode it is now".
Under-staffing was a large interest for Kelly Hopkins, who has been a caregiver for 25 years successful Liverpool, arsenic good arsenic the fiscal struggles of her colleagues.
"They're having to usage nutrient banks, they're coming successful cold, they're going without nutrient to provender their children, it's conscionable crazy," she said.
In England and Wales, astir NHS unit person received a wage emergence of astir £1,400 this twelvemonth - worthy astir 4% connected mean for nurses.
The governmental concern successful Northern Ireland meant determination was a hold successful processing the summation - but nurses should person backdated payments earlier the extremity of the fiscal year.
The Royal College of Nursing (RCN) wants a larger rise, of 5% supra the RPI ostentation rate, which presently stands astatine 14%, saying its members person received years of below-inflation wage increases.
The authorities says it has followed the proposal of the autarkic NHS Pay Review Body, which said successful July NHS unit should person the £1,400 increase, with somewhat much for the astir experienced nurses.
The RCN has criticised this assemblage for not being autarkic enough. It is made up chiefly of economists and quality resources professionals.
Welsh ministers said they were incapable to participate wage talks without other backing from the UK government.
In Scotland, the RCN's onslaught enactment was "paused" aft ministers made a caller connection worthy conscionable implicit £2,200, oregon 7.5%, a twelvemonth for astir NHS staff. Nurses person been asked to ballot connected that deal, with results owed adjacent week.