Yorkshire ambulance workers are on strike today in their long-running dispute over derecognition of their union, downgrading of jobs and attacks on working conditions.

The Unite union's 450 members in the Yorkshire Ambulance Service (YAS) began a 24-hour strike at midnight after an overwhelming vote for strike action.

They will walk out again from 3pm to 7pm on Monday.

Unite officials said the attack by management was part of a nationwide pattern which included widespread introduction of private ambulance services.

The YAS workforce is divided between two unions, Unison and Unite.

Unite resisted the downgrading of ambulance workers' jobs and was derecognised by bosses a year ago.

Management recently stepped up attacks by introducing 12-hour shifts and shorter breaks, transferring staff to distant stations and axing subsistence allowances.

Unite Yorkshire ambulance branch secretary Debbie Wilkinson said bosses were replacing skilled staff with poorly trained "assistant practitioners."

"YAS repeatedly states that this role works well in other services - yet time and time again this is proved incorrect."

"East of England ambulance service have recently abandoned the role as not fit for purpose, following others such as West Midlands, London and the north-west.

"It is simply not fair to these staff or their colleagues to expect them to learn their craft on the job.

"All this leads to a demotivated and increasingly tired workforce that is less clinically qualified to deliver excellent patient care."

She said there had been an "incredible acceleration" in the use of private ambulances nationwide - with Yorkshire taking the lead.

And nationally ambulance bosses are also attacking unions which resist their plans.

"Unite were derecognised within London Ambulance Service and now YAS have derecognised both the GMB and Unite, but this has not happened in other areas of the NHS health sector on such a huge scale," said Ms Wilkinson.

"This must be seen as an attempt to silence our members and cannot be tolerated."

Unite has appealed for solidarity on picket lines and at demonstrations.

Pickets are in action in Leeds, Wakefield, Rotherham, Keighley, Barnsley, Doncaster and Bridlington.