The police could be drafted in to ferry patients to hospital over the festive period after ambulance crews in Wiltshire voted in favour of strike action.

Forty-three per cent of Great Western Ambulance Service (GWAS) staff could stage a walkout after Unison members carried out a ballot on strike action at the end of last week.

Despite only seven per cent of the trust's staff having voted for strike action, all 562 Unison members could refuse to work for a two-hour period on Christmas Day, Boxing Day, New Year's Eve and New Year's Day - putting a huge strain on the emergency service.

But the trust last night assured the public that a contingency plan will be put in place should a last-minute compromise fail to materialise.

"As a trust we remain committed to resolving any dispute with our unions promptly and openly," said a statement issued by the trust.

"We are therefore deeply disappointed that despite constructive, face to face talks with Unison where agreement was reached on seven out of the 10 issues raised, the union intends to carry out strike action on four days over the Christmas and New Year period.

"Given the progress made between the new management team and Unison in reaching a resolution on a majority of issues, we consider Unison's action to be disproportionate to the situation we find ourselves in.

"We are currently in conversation with St John Ambulance, private companies and the police.

"We are also looking at the possibility of using clinically-trained managers. We are doing everything we can to maintain minimum levels of cover during this period.

"We continue to seek opportunities to resolve this dispute before the industrial action begins."

But Swindon paramedic Phil Davis, the Unison representative for GWAS, said the strike action was inevitable after the trust failed to resolve major issues relating to pay and conditions.

He said that even though 85 per cent of Unison members voted for action short of a strike, more than 50 per cent of those also voted in favour of strike action - the mandatory number required for a walkout.

"There are a number of issues why members voted for strike action, one of the main ones being that staff are only being paid a flat rate for working on Christmas Day and bank holidays and that the trust owes us money for subsistence pay," Mr Davis said.

"I can't think of many organisations where that is the case.

"It is always disappointing to go down the route of strike action. I have been involved in two major disputes before, but we do seem to get forced into it."

Unison, locally, is requesting a "one-off" additional payment for staff who work on Christmas Day or Boxing Day, but the trust says that payment for working bank holidays and unsocial hours is already included in the new Agenda for Change pay deal and that no additional funding has been allocated for Christmas Day or Boxing Day.

The trust also said it is in the process of paying frontline clinical staff for excess work carried out before Agenda for Change was implemented and that it disputes Unison's claims for subsistence payments.

It has also pointed out that ballot papers were not sent to all Unison members.

On Saturday, the Adver revealed how disaffected GWAS ambulance staff set up a blog to air their concerns over pay and conditions to management at the trust.

One poster described the trust's ambulance stations as in a "state of neglect".

And Mr Davis said that pay was not the only factor that has prompted the strike action.

He said: "The trust closed its only paramedic training station in Chippenham and that has meant that many ambulances are going out without a paramedic on board and that has a big effect on patient care."