The question is, should casual workers be paid holiday pay? I’m pretty sure the answer is yes, but can anyone give me a reference to the legalities of it?

ALL workers accrue holiday pay, at the same rate.

Google expert here.

You have the right to take statutory paid holiday from work if you are a worker. This includes people who work full-time, part-time, agency workers and casual workers.

As a casual worker for British Cycling, I get an itemised payslip, showing pay plus holiday pay, so I my question is, shouldn’t any other employer be doing the same? Is it actually illegal not to?

It’s unlawful not to, yes.

You actually aren’t allowed to just pay people a bit more each time, either – which seems to be what you’re saying BC do. Employers are required to actually give people paid time off. Subtle difference, but it’s not the same thing.

Obviously you can’t force people to take their holiday but they must be able to do so. And if they come to the end of their contract and haven’t taken it all, they must be paid in lieu.

The BC work is just casual, so they are actually correct in paying an extra amount as holiday pay.
Unfortunately, my other casual job hasn’t been paying holiday pay, so what I think I’m after is a statement of the law that requires an employer to pay it – or is there some “get-out clause” available for some employers?

There’s some good stuff on the Gov.uk site, including a calculator.