A planned ballot of British Airways cabin crew on resolving their dispute with the airline has been suspended, dashing hopes of an end to the bitter row.
Unite had been due to ask its 11,000 members whether they wanted to accept a suggested deal, with voting expected to be held in the coming weeks.
But leaders of the union's cabin crew branch decided earlier this week they could not support recommending the offer.
Unite's joint leader, Tony Woodley, said that any sense that the offer was being presented to cabin crew over the heads of "unwilling representatives" would be damaging to the union.
"Under these circumstances I have suspended the ballot on the offer and will meet with all of our cabin crew representatives as a matter of urgency to consider the next steps," he said.
The understanding was that the offer would be recommended for acceptance by union leaders when it was put out to a ballot of cabin crew.
The dispute began over a year ago, initially over cost savings, but it became embroiled in rows over disciplinary action taken against cabin crew who went on strike, who were also stripped of their travel concessions.
Unite members took 22 days of strike action earlier this year, costing the airline £150 million and disrupting travel for passengers.
Under the proposed deal, the union would have to drop legal action on behalf of members who have been disciplined and agree to a period of no industrial action before the travel concessions were fully restored.