Lecturers' leaders in England are considering a boycott as an "extreme option" in response to fees for compulsory registration, with their professional body more than doubling in a year.
The Institute for Learning (IfL) maintains the fee increase from pound;30 to pound;68 a year is necessary as it moves from the Government covering members' costs to the more uncertain and expensive process of charging individuals.
But lecturers have questioned whether they receive significant benefits beyond an annual form-filling exercise to demonstrate their completion of the compulsory 30 hours of professional development.
Barry Lovejoy, head of FE at the University and College Union (UCU), said complaints about the decision had flooded in and the union would consider measures including boycotting the IfL, a move that would mean lecturers breaking the law passed in 2007 requiring all FE teachers in England to register.
Mr Lovejoy said: "We will consider all options. That might mean a boycott - that's the most extreme option. At a time when FE lecturers' income is under pressure, to say the least, with a pay rise of just 0.2 per cent and the prospect of imposing pension contribution increases on them, they are now faced with a bill for a body they are required to join. But it's a widespread view among our members that they don't benefit from it."
The IfL's own survey of members shows that 61 per cent believe the value of benefits is good or excellent, but it was taken when the cost of membership was met by the Government.
IfL chief executive Toni Fazaeli said the organisation was trying to make the fees affordable through tax relief, which reduces costs by a fifth for most members, and with a transitional deal with the Government which stretches the first payment to cover 18 months' membership rather than a year.