In the UK anywhere I tried to become an employee in the last 5 years also asked me to sign the "I am ok to work more than 40 hours" addendum, and it was a condition with the offer.
No employer I've seen has ever questioned it, they know it'd be illegal for them to actually force you to opt-out your of your rights. If they put it in writing that it was a conditional part of employment they'd be in hot water.
They're just hoping you just sign away your rights "for free" so to speak.
As of lately, I've seen some web-based signature systems (adobe something something docusign iirc?) and with such systems crossing lines is not an option anymore.
In the esig case, you’d need to talk to HR to have the provision removed.
Yes I think that was implied by the original poster. The company has to counter-sign the modified document, which is why they always get you to sign it first, so they can review before they sign.
Never had a job where that wasn't a clause in the contract.
As you said, the Working Time Regulations Act 1998 is the UK law implementation of the EU Working Time Directive 2003.
If a potential employee isn't willing to agree to work more than 40 hours they either don't take the job, or take the job but refuse to work those extra hours and risk being fired. Being fired is never fun, but the employee is still better off ignoring the contractual obligation there if it was a deal breaker anyway.
There are contract rates for how much overtime should be paid. Just ask to be paid.