Can my employer double my notice period like this?

[serenzrp]

Hi everyone, I had my annual appraisal today and my line manageress told me my notice period was doubling to 8 weeks notice. She gave me a piece of paper stating this which she told me to staple to the back of my current contract of employment because it would replace the original paragraph. She never asked me to sign this new piece of paper or anything else.
So I was wondering (?) legally (?) if I got a new job could I still get away with only giving 4 weeks notice because that was on the original contract of employment I signed last year?
Looking at other similar questions needing more information, I work in an office and nothing I do would be considered "specialised", in fact the "big boss" often calls members of my team "unskilled" because we're "not sales staff making money for the business". If I was paranoid, I'd think that "the management" knew I am planning to leave and maybe this is their way of telling me that I can't? Well, not very easily or quickly anyway.
Anyway, thanks for any help or advice. :-)

[jennifer_cro]

Strictly speaking, anyone can walk out from their job without giving notice although you may forfeit your rights to accrued holiday pay. Very few employers sue an ex-employee for not working their notice, particularly the "unskilled" ask your boss puts it.And thats what they would have to do as it's a breach of contract on your part.

If your employer wants to change your contract they must inform you and the have to get your consent that you agree to it. However by continuing to work without complaining that you are not happy with your new notice period you could be seen to have agreed to the change as you have not raised it as an issue.

[undercovers]

your employer can change your contract terms BUT only if you agree - in this case your agreement could be oral or implied by your attacking of the new terms to your old contract... you are perfectly free to refuse the change though, or negociate another one

[WoWo]

As the others said just make it clear that you are unwilling to accept the new notice period, as always add in a little line that you know what your rights are on this (and other) matters are.

If they push it you could say given the extra commitment you would require more money to sign what is in effect a new contract.

But whenever I have had to leave a company early I have tended to pick a middle ground and leave earlier than my minimum notice period.