Mayor Scott D. Galvin’s bid to use a state law to revamp the city’s employee health plan has been derailed by the City Council. By a vote of 5-4, the council recently decided not to send the proposal to committee, effectively halting its consideration, at least for now. The 2011 state law allows cities and towns to make changes to their health plans without union agreement, provided they are comparable with those offered by the state’s Group Insurance Commission system, or to transfer insurance coverage to that system. Galvin said the law could save Woburn and its employees about $1.7 million in the first year. In a statement following the council vote, he said he was “amazed and disappointed” by the action. “This is a critical and urgent financial issue for the city of Woburn. For a majority of the City Council to refuse to face this reality — or even discuss it — is irresponsible and simply kicks the difficult but necessary measures to address this growing problem down the road for others.” Ward 1 Alderwoman Rosa DiTucci, who voted with the majority, said the mayor’s plan would be “detrimental to people who have catastrophic illnesses and might need to go to a specialty care center outside of Lahey [in Burlington] and Winchester Hospital. And she said the plan “would give one person, whether this mayor or any other, the unlimited ability to make changes to the health plan without any input whatsoever.” Galvin said he is not abandoning the proposal. “We are going to step back, weigh the options, and see what the best way to proceed is here,” he said.