Thanks all again! Some really good advice.
I contracted for 11 years so know the score, especially around IR35 etc. As I said, I loved it just going to different places, sorting the mess out and moving on. No office politics or having to monthly "personal development" nonsense either. Great to be able to take time off and everywhere I went they all wanted me to stay on as a permie... but then you know you'll end up having to "reach out" to someone to discuss whether someone else deserves a 1.5% or 1.75% pay rise ha ha! No chance! Great money and maybe in a few years I'll go back into it. At the moment though I've got a young family and need to be around.
I've got another "consultation" now with HR and a Director. It's not been escalated apparently, but my boss is too busy to do it so the Director is doing it! Hmm!
My plan, so far, is to reject the clauses on the basis it is weakening my financial position. Firstly because I would be volunteering to have my pay cut if the company is struggling. Secondly, because if I want to leave a 1 month notice period is more valuable to the next employer.
As I said, I don't want to leave they are a good company and I've been looked after really well. The people are great, but this has taken my really by surprise.