Legal representation works both ways. It could be you in dispute with your employer, or someone you employ in dispute with you. You are also subject to a considerable amount of safety legislation, and could be prosecuted by HSE, Environmental Agency, DTI or other statutory bodies and enforcers. Representing yourself in a legal dispute is possible, but requires a considerable amount of experience and self confidence so is not suited to everyone, which is why Trade Union membership is useful.
Possibly the best Trade Union for professional engineers is PROSPECT - see http://www.prospect.org.uk
- which represents engineers in a variety of disciplines. Prospect and other Trade unions also do rather more than negotiating terms and conditions. They also make representations to government on many social, environmental and educational aspects related to their members interests, and their magazines, web-sites, and other publications often contain excellent information on legislation and technical matters.
They will also advise and assist members and their families in the event of serious long term injury, or bereavement.