The Lecturers Employment Advice and Action Fellowship is a single issue group launched to challenge the legality of contracts imposed on staff. The union is not recognised nationally and must tout around colleges for voluntary contributions to meet its costs.
But leaders of the Association of Colleges are viewing the case very seriously. "The implications of the decision of the employment tribunal in this case could be far-reaching," they say. If the case involving Havering College goes against the employers, it could cost millions in compensation.
The tribunal in July will contest LEAF's claim that new contracts were illegally forced on college lecturers. They will argue that the terms and conditions of old Silver Book-style agreements should have been preserved when colleges left local authority control.
LEAF will rely on a ruling last October which found that employers who took over an existing business could not alter the terms of employment unless there was a significant change in the business.
The tribunal will also consider LEAF's claim that because they depend on government funding, colleges are subject to European Union directives.
LEAF was formed in 1995 and has a membership of "hundreds rather than thousands" in some 50 colleges, according to its general secretary David Evans.
Mr Evans, a business studies lecturer at Havering College, said he was confident of winning the case. If LEAF's case against Havering College is successful, Mr Evans estimates the cost of reimbursing the increased workloads, lost holidays and foregone pay rises across the sector could amount to pound;500 million.
Mr Evans, who has not had a pay rise since incorporation because of his refusal to sign a new contract, believes LEAF can become a viable alternative to NATFHE, the main lecturers union.
He said: "They have painted themselves into a corner. Mr Mackney (Paul, NATFHE general secretary) has called an end to the six-year dispute but he has no mandate to do so."
An AOC spokesperson said: "We don't think they have a leg to stand on. They don't have a chance in hell of winning but from the point of view of our members' interests we have to follow it through."