I've come up against this before (Scotland, but broadly the same employment law). My understanding is that this term would not be considered reasonable, and as

I've come up against this before (Scotland, but broadly the same employment law). My understanding is that this term would not be considered reasonable, and as a result would not be enforceable. However, you'd need to either opt out or discuss this with a solicitor if you were planning to do anything which might come under that umbrella, as it would likely be expensive and messy if you had to fight, regardless of who's actually correct. In most cases, I've found this has simply been thrown into an employment contract as part of a lawyer's off-the-shelf documentation, and will be removed upon request.