More than 3,500 ambulance workers across the region will strike on Monday – but health bosses have stressed that anyone needed emergency treatment should still call 999.
Paramedics, emergency care assistants, call handlers and other staff will walk out in the ongoing row over pay.
The GMB union, which represents ambulance staff, is taking action over the government’s four per cent pay offer.
GMB national secretary Rachel Harrison said: “Ambulance workers are angry – in their own words, ‘they are done’.
"Our message to the government is clear – talk pay now."
The strike on Monday will last for 18 hours in the region, from 6am to midnight. Picket lines will be manned from 6am until 6pm.
NHS England advice is for patients needing health advice on Monday during the strike is, as a first port of call, to use the NHS 111 hotline – and to call 999 in a life-threatening emergency.
It adds: “General practices, community pharmacies and dentists are not impacted by strike action and patients should continue to access these services as needed on strike days.
“999 should only ever be dialled in an emergency – that’s the case every day but it’s even more vital that our services are used wisely during any period of industrial action."
Mark Ainsworth, director of South Central Ambulance Service, said only about 230 of 4,500 staff will be working on Monday.
“The impact will mainly be our non-emergency patient transport service,” he said.
More strikes are planned for March which may be coordinated with fellow ambulance union Unite.