The health union Unison has announced new strike action and warned there could be no “pick and mix solution” to the NHS dispute, after it was excluded from talks between the health secretary, Steve Barclay, and the Royal College of Nursing. Unison said up to 32,000 of its members across the NHS in England, including ambulance staff, paramedics and some nurses, would strike on 8 March, in what it called a “serious escalation” of the dispute. “There can be no pick and mix solution,” said Unison’s general secretary, Christina McAnea. “NHS workers in five unions are involved in strike action over pay, staffing and patient care. “Choosing to speak to one union and not others won’t stop the strikes and could make a bad situation much worse. Unison and other health unions were taken aback on Tuesday, when the Royal College of Nursing (RCN) and the health secretary issued a joint statement saying the RCN would suspend planned strike action while pay talks took place. RCN members’ pay is covered by the NHS-wide Agenda for Change agreement, which includes many thousands of other NHS workers. The health minister Maria Caulfield appeared to suggest on BBC Politics Live on Wednesday that any deal agreed with the RCN would have to be applied NHS-wide. “It wouldn’t be necessary that nurses are a special case,” she said. Caulfied added: “If you put up [pay for] nursing by 1% on Agenda for Change, that’s Agenda for Change across the board.” Previous talks with Barclay have included other unions involved in NHS strike action, including Unison but also Unite and the GMB. Rachel Harrison, the national secretary of the GMB, which represents striking ambulance workers, responded to Tuesday’s announcement of talks by accusing the government of pursuing “divide and rule” tactics. “This backroom deal with some sections of the workforce is a tawdry example of ministers playing divide and rule politics with people’s lives,” she said. Better than expected public finances data on Tuesday may have helped to open the way to a more generous pay deal for NHS staff, with some reports suggesting 5% is under consideration. The government is keen to put the focus on pay for the coming year, 2023-24, but has not ruled anything out in the RCN talks, in what appears to be a softening of its previous position. Responding to Unison’s statement, the shadow health secretary, Wes Streeting, accused the government of “mishandling” the NHS dispute by singling out the RCN. “They should be calling in all of the Agenda for Change unions for pay talks to avert the risk of further strike action affecting patients,” he tweeted. A Department of Health source said Barclay was keen to have discussions with all the NHS unions involved in the dispute. However, the other health unions say they are yet to receive any invitation.