As a pert-timer in FE I was persuaded to join the FE Union (NATFE), but when the management informed me at a minute's notice, that I was no longer needed, the Union officers weren't interested. All they wanted was my membership fee.
Years later, when I'd been working full time in a different College, still a member of the Union, the College decided on redundancies. As no volunteers came forward, they made them compulsory and, about 18 months before I reached retirement age, I was compulsorily redundant, with no support from the Union - a very left-wing organisation who were more interested in supporting striking dockers than their own members. When, in retirement, I became a CAB adviser and learnt more about employment law, I realised that I'd had better grounds for appeal than I'd previously believed, but it should have been my Union's job to advise me about that. I'm not against Trades Unions - far from it - but there are some that are (or were) useless.