You may certainly decide to go it alone, by taking the matter to an Employment Tribunal. For this you should probably engage a solicitor who will advise you, prepare the court papers and manage your claim throughout. The solicitor, in turn, may wish to engage a barrister to advise and/or to represent you at the Employment Tribunal. You would, of course, have to bear all your costs alone and, even if you were to win, you would not able to recover your costs. Some employment claims can be brought in the civil courts rather than in an Employment Tribunal. These are typically breach of contract claims. Again, you would probably ask the solicitor to deal with the matter and, again, he may wish to engage a barrister to represent you at the hearing. Unlike in the Employment Tribunals, if successful you could seek an award for your costs, but you may well be advised that the amount recoverable is unlikely to exceed 60-70% of them. Note
: If you have worked for multiple umbrella companies, you would need to issue a separate claim against each of them.
You should be aware, however, that the umbrella companies would doubtless defend an individual claim trenchantly, and it is easier for them to do so on an individual claimant basis.
A well-funded and strongly-fought claim on behalf of a group of claimants will be taken much more seriously by the umbrella companies, and there may well be a better chance of achieving a settlement of a group’s claim by negotiation.