Campaigners are seeking legal advice after West Midlands Ambulance Service yesterday agreed to close two of its five control centres.
More than 40 angry staff, local politicians and campaigners attended its board meeting at Walsall Football Club's Bescot Stadium, where the reconfiguration of emergency operation centres (EOCs) was rubber-stamped in a unanimous vote.
At present, 999 calls are answered at five regional bases - Brierley Hill, Leamington Spa, Shrewsbury, Stafford and Bransford near Worcester.
The trust's decision follows a three-month public consultation over its plans to sell off sites at Bransford and Shrewsbury, and expand EOC capacity at the three remaining centres from 62 to 110 workstations - at a cost of £3 million.
Trust bosses said the project will start next summer and they hope reconfiguration will be completed by December 2008.
However, health workers' union Unison is talking to its lawyers about the possibility of legal action and before chairman Sir Graham Meldrum asked the 17 board members to participate in a swift vote, a prospective Lib Dem MP branded the consultation as "a whitewash from start to finish".
Richard Burt, parliamentary candidate for West Worcestershire, urged chief executive Anthony Marsh to "rip it up and start again".
"We have taken advice from lawyers on the possibility of a judicial review if the board decides to close Bransford and Shropshire," he said.
Two independent reviews were presented at the meeting, and analyst Richard Miles disputed earlier claims that consultation response figures were 'fudged' to show a higher level of public support.
Before the vote, the plans were amended to include safeguards that ensure ambulances do not "drift" into urban areas to assist other localities.
Sir Graham said: "Nobody on this board has taken this decision lightly and I would to like to thank for all your efforts and hard work on this."
After the meeting Ray Salmon, Unison's regional spokesman, confirmed lawyers were considering a judicial review "into the trust's processes and decision".
He added: "I am not surprised by this decision as I expect it was taken long before today, and this meeting was stage-managed beyond belief. The last-minute amendment was an appeasing sop just to make it look fair."
Campaigner Karen Ashcroft, an emergency call taker at Bransford, stormed out sobbing after the vote. "I just feel so angry about what has happened here today. I feel nobody has listened to us, or even read the documents judging by some of the questions board members were asking," she said.
Tracy Jones, an ambulance worker and Unison representative based at Shrewsbury, said: "This is a sad day as another little bit of our county's service is dissolved."
Afterwards Mr Marsh said: "No control rooms will close before next summer and we will phase in what happens next, but we hope to have completed the reconfiguration by the end of 2008. Some might opt for redundancy, but we want to retain all staff in one form or another, either in their current jobs or by retraining them. It's in no one's interest for the service to deteriorate."