Staff at Great Western Ambulance Service have postponed industrial action following a legal challenge by the trust but could still stage a full walk out.

Members of Unison were due to begin a work to rule at midday yesterday after weeks of talks failed to resolve their objections to changes in shift patterns.

But the union withdrew the threat after the ambulance trust said the notice of industrial action was not legally secure. However it issued a fresh notice earlier this week that its members would now take action next Wednesday.

Unison’s regional organiser, Simon Newell told HSJ the legal challenge had strengthened members’ resolve and a strike could not be ruled out if talks on Monday did not resolve the issues.

He said: “The branch hasn’t decided what action to take. Hopefully the talks on Monday will bring a resolution and we won’t have to do anything.

“We have had a lot of feedback from members in the last seven to ten days and it’s quite clear that they are very unhappy indeed.”

Mr Newell said about 600 of the trust’s 950 frontline employees were union members and 96 per cent had voted in favour of industrial action.

They are angry at plans to stagger shift start times and replace the current entitlement to two half hour breaks during a twelve hour shift with one hour long break.

The union claims changes to shift patterns have been forced on staff, despite the union registering a trade dispute in accordance with the trust’s procedures. It also says the change resulted in the trust reducing its compliance with the Category A target which requires ambulance trusts to attend 75 per cent of the most urgent calls within eight minutes.

The trust disputes this and says any drop in performance is comparable with that of other trusts due to winter pressures.

The new notice of industrial action came despite a long meeting at the Advisory, Conciliation and Arbitration Service (ACAS) in Bristol yesterday.

Trust chief executive David Whiting said: “We arrived at [the] meeting with a comprehensive package of proposals that addressed the range of issues raised by UNISON.

“It is therefore extremely disappointing that the meeting ended with very little progress and Unison re-issuing their notice of action to us.

“We remain committed to avoiding the need for industrial action as that will do nothing to benefit the many hundreds of patients we attend every day. To that end, we will go into Monday’s further meeting with Unison with every intention of finding a solution to this dispute.

“In the meantime, we will continue to finalise our contingency plans. That includes asking Unison to clarify the action they plan to take to ensure that we are able to provide a safe and effective 999 service to everyone who needs us.”