Paramedics and university staff are staging further walkouts today over pay, jobs, pensions and conditions.
University staff will continue a 48-hour strike despite an announcement of fresh talks aimed at resolving the dispute.
Ambulance workers are going on strike in five regions in England: London, Yorkshire, the South West, North East and North West.
Unison said the action “follows hard on the heels of strikes involving ambulance staff, nurses and physiotherapists organised by four other health unions”.
Nurses at 73 trusts in England took action on Monday and Tuesday, and physiotherapists on Thursday.
Read more: Who is taking industrial action in 2023 and when?
NHS Medical Director Sir Stephen Powis said: “NHS staff have made incredible efforts to keep critical services running as best they can, but the reality is that today’s strike comes at the end of the biggest industrial action in the history of the NHS, and there has been little time to recover between strikes.
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“We are incredibly grateful to the public for their care in how they use the health service during strike days, but we are seeing demand rising compared with previous days of industrial action.
“Disruption is inevitable, however it is vital that people do not put off seeking care and dial 999 in a life-threatening emergency and come forward for treatment using 111 online for non-life threatening care, as well as using local pharmacies or General Practice.
“Anyone with an appointment should continue to attend as planned unless they have been contacted to rearrange.”
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Members of the University and College Union (UCU) will walk out at around 150 universities.
UCU and four other higher education unions – EIS, GMB, Unison and Unite – are due to meet employer representatives for talks next week.
The union said planned talks at Acas, the conciliation service, are intended to address issues including pay, equality, job insecurity and workloads.
UCU general secretary Jo Grady said: ‘We are pleased the employers have agreed to enter the Acas process in order to try and resolve our dispute.
“The union has been clear, we need an offer that addresses the key issues affecting our members – specifically on casualisation and workloads. We haven’t had that yet.
“The sector has more than enough money to pay and treat people fairly, and employers have the power to do so.
“I am incredibly proud of UCU members whose dedication to improving their working standards and education has gotten us this far.”
Friday’s strike will be followed by more walkouts throughout February and March.