PEOPLE are being urged to only call 999 for an ambulance in an emergency as strike action takes place today.
The 12-hour strike by 500 ambulance staff will begin at midday.
The industrial action has been taken after staff raised concerns about the introduction of the new emergency care assistant roles, who will work alongside paramedics, having only had three to six weeks training.
The decision is part of plans to cut the budget by £46m over the next five years.
The Yorkshire Ambulance Service NHS Trust also decided to no longer recognise the Unite union.
But the trust insists plans are in place to safeguard patient safety and less than 10 per cent of the staff will be involved in the strike.
Trust chief executive David Whiting said: "Our contingency plans are focused on providing a safe, responsive and high-quality emergency service to patients and this will always remain our top priority.
"I would like to reiterate that I remain deeply concerned over this type of action, which I know is of concern to all of our accident and emergency staff, who are very committed to patient care, and will place many of them in a very difficult situation.
"I do not believe that industrial action in this form is in the best interests of patients, and it is deeply concerning for a trade union representing ambulance service workers to strike without making any concessions to patient safety.
"Our focus will be on taking steps to maintain operational cover to sustain effective and safe services for patients calling upon us for assistance."
The trust has appealed for people to use the service only if really needed.
Mr Whiting said: "This action will undoubtedly place strain on our 999 service and, therefore, we remind the public to use the service wisely and asks people to only call 999 for an ambulance in an emergency when it is obvious that someone has a life-threatening or serious illness or injury."
But Unite has repeated its call for more talks.
Regional officer Terry Cunliffe said: "Our members are increasingly concerned about patient safety because of the downgrading of the current skill level on NHS frontline vehicles in Yorkshire.
"We call, yet again, on the blinkered, hardline management at the trust to enter into meaningful talks with Unite.
"The continuing refusal of the management to discuss patient safety – which led to the derecognition of the union – has left our members with no option, but to take further industrial action."
The latest action follows a one-day strike on April 2 and there could be another 24-hour stoppage on Saturday, June 22 if talks are unsuccessful. Unite members are also currently operating a continuous overtime ban.
Mr Cunliffe said: "As clinicians, they feel very strongly about what they see as the downgrading of the frontline response to emergency calls and the serious effect this will have on patient care in Yorkshire."