[Closed] HR experts - the "You may be required to work such additional hours" clause

Morning all

There's been some good HR advice on here in the past; I wonder if any of you can help?

I have been backed in to a corner by my employer, and against my principles I am being forced to think of some potential fire-with-fire techniques.

I am contracted to 37.5 hours, with the usual clause of "You may be required to work such additional hours to fully perform your job in accordance with the needs of the business."

In reality I am expected to, and have worked 42.5 hours every single week for as long as I can remember.

Is there any mileage in claiming the additional hours on the basis that it is not a case of "may be required" but actually the week in week out reality?

I don't actually want the money, simply to make a point.

Thanks

EDIT - sorry wrong forum initially.