UNIONS have been branded "heartless" after they rejected a deal that would have given ambulance staff extra payments for responding to emergency calls during breaks and ended a long-running dispute brought into sharp focus by the deaths of a woman and a toddler.

Members of three unions negotiating with the Scottish Ambulance Service (SAS) voted two to one to turn down an offer of a one-off lump sum of £1500 plus £100 for every time a crew's rest break was interrupted.

The unions claim the dispute is not about money, and say their members need designated rest periods in order to provide an efficient service.

Unions and the Scottish Government have been at loggerheads over the issue since 2004, when the wide-reaching Agenda for Change reforms in the health service reduced their working week to 37.5 hours.

But last night the decision, taken by members of the Unite, Unison and GMB unions, was attacked by Conservative health spokesman Jackson Carlaw, who accused them of "blind self-interest".

Mr Carlaw said: "It is ludicrous that the unions have rejected what was a fair and reasonable deal. The general public will find it incredibly hard to understand why these workers are having tea breaks when people's lives are at stake.

"This heartless attitude is costing lives and Nicola Sturgeon needs to get a grip on this issue and thrash out a deal to prevent any further tragedies."

The controversial issue of ambulance crew rest breaks was thrown into the spotlight by the death, in 2010, of Mandy Mathieson, 33, of Tomintoul, Moray, who suffered a heart attack.

It later emerged that ambulance technician Owen McLauchlan had chosen not to respond to a 999 call to come to her aid, despite being only a two-minute drive away, because he was on a meal break. Instead, a crew 21 miles away in Grantown-on-Spey responded.

And last April, three-year-old Martyn Gray died at Drummond Castle, near Crieff in similar circumstances. A crew taking a break 10 minutes away was not called and another crew took 48 minutes to reach the family.

Both deaths prompted widespread outrage, but several deals aimed at resolving the situation have collapsed.

Fresh talks will now be held between the three unions and the SAS on Monday in a bid to break the deadlock.

Margaret Watt, of the Patients Association Scotland, said: "I sympathise with the unions and understand their members need breaks, but a common sense approach needs to be taken."

Ms Mathieson's brother, Charlie, a firefighter, said of the breakdown: "I'm disappointed, but I'm not surprised. If we're called out during a break in my line of work we just resume it when we return, but that is often not possible for ambulance crews, especially rural ones."

Unite Scottish Secretary Pat Rafferty said the demands of the job meant ambulance workers frequently exceeded their contracted hours, and that a new deal is needed.

Unison Scotland organiser David Forbes said: "Our members need to be able to switch off for a part of the day in order to deliver the best possible service for patients."

A spokesman for the SAS said: "A very good offer was made to staff and it is disappointing that this has been rejected. We will meet with staff representatives on Monday to continue the dialogue."

Jackie Baillie, Scottish Labour's health spokesman, called on the SNP Government to work harder to resolve the dispute, saying it was time it showed "real leadership" on the issue.

Contingency plans, which allow for staff to be disturbed during their rest break in the event of the most serious calls, will continue to operate.

The Health Secretary said the breakdown was "disappointing". Ms Sturgeon added: "I have been very clear that I want this situation to be resolved as soon as possible."

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