If I work part time and I attend training on a day that I wouldn't normally be working should I still get paid?

So for example if a part timer attends a course on a day that they would not normally be working they are entitled to be paid for that day. If your pay does not vary with the amount of time, you are entitled to be paid what you would have received had you been at work excluding overtime pay. If, however, you are employed on an hourly paid or zero hours contract you are entitled to receive your average pay.

It will also depend on what your local facilities agreement says or what you can get your employer to agree to. Many institutions will allow it, especially if you argue less favourable treatment than a full time member of staff.

There is a really good example here:

UCU Training Update - Spring 2010 [294kb]

For union health and safety reps there are specific legal cases quoted for safety reps in the latest Safety Representatives and Safety Committees publication (brown book).

And more info here: ACAS code on time off to train