College managers will vote next month on whether to join forces with the Association of Teachers and Lecturers (ATL), as the rising cost of representing members threatens their union's survival.
The Association for College Management's (ACM) deal with the ATL would create a new body, the Association for Management in Education (AMiE), within the teaching union - if members agree.
The ACM argues that the transfer will allow it to weather the storm of cuts in further education, respond to the increasing overlap of schools and colleges and provide it with the resources of a bigger organisation to help members.
The ATL hopes the deal will mean it can offer union membership that lasts for the whole of a career, from day one as a teacher to school or college leadership, instead of losing members when they get promoted.
But rivals, which have their own interest in the outcome, question whether the merged union will be able to reconcile the conflicting interests of education leaders and their staff.
Peter Pendle, ACM chief executive, said the union continued to grow but faced tough challenges which meant merger was the best option. "We have recognised for some time that we are going to be facing difficult times for our members," he said. "There are up to 7,000 job losses - maybe as many as 10,000. We want our members to have a professional representative if people are in trouble. That's quite a high-cost model."
The ACM considered several options, including merging with the University and College Union (UCU), the largest union in FE, but the very different ways in which the two bodies greeted incorporation in the 1990s meant there was a difficult history. The ATL was the closest fit, he said.
Mr Pendle, who took over as chief executive in 2001, said the ACM had grown from just four or five staff to 16 today. Its membership, currently around 4,000, has also been growing at 1 or 2 per cent per year, despite the rapid turnover of a largely older workforce, many of whom retire each year.
But its main concern was the funding reduction and the job losses that entailed, Mr Pendle said, adding that redundancies would soon make the ACM's recruitment job even harder.
"There's no doubt that we will lose members at a greater speed," he said. "At the moment, we lose 12 to 15 per cent of them a year - we have to recruit just to stand still."
His view is backed up by the Association of School and College Leaders, one of the ACM's competitors, which claims that some people as high- ranking as assistant principal are already at risk of losing their jobs.
Other union members will be responsible for managing the cuts without damaging their colleges' educational provision. Trying to help them compete for a greater share of the public money currently paid to private providers or higher education was another priority for the union, Mr Pendle said.
Despite its growth, the union says the demand for support from members has grown even faster. It has had to hire three extra officers to cope, but will not be able to afford these in the long term without the merger, it says.
A document for members explaining the change does not mince its words: "To put it bluntly, the stark reality is that ACM's survival cannot be guaranteed without the transfer."
The ACM is not in a unique position: mergers are common among unions. The UCU's amalgamation of representative bodies for further and higher education took place in 2006, while the UK's largest union, Unite, was formed in 2007.
Competition is intense, according to the ACM, which told its members that it needed to counter the "aggressive recruitment tactics" of other unions.
Mr Pendle said: "It's a competitive market. There are fewer senior posts across education. All sorts of organisations are looking at how they increase their membership."
However, one leader of a rival union said it was baffled by the move and could not envisage management and teaching union members seeing eye to eye.
"They're going to lose their unique selling point, which is that they speak for senior people only," he said. "Teaching unions can be very critical of management, as you'll know if you've been to one of their conferences. They may find this is a mistake."
But the ACM believes there are safeguards which prevent it from being hijacked by teachers and lecturers. The AMiE will set its own policies and have its own elected council, as well as a separate identity, and union leaders believe that the ATL and the ACM are aligned closely enough to avoid significant conflict.
And if the survival of the ACM is at stake, one question members will have to ask themselves when they vote next month is: can they afford to vote "no"?