You are correct MOR. The company can change your terms and conditions but the changes have to be within reason.
For example they can change the amount of shirts they supply you with each year because the effect on employees is minimal. If you remember the company did reduce the amount they provided you with a few years ago from six to four. They can do this because four shirts per year is a reasonable amount.
They cannot take away your entitlement of shirts away completely as the supply of uniform is written into your contract.
Taking away leave or reducing salary or altering pension benifits etc. is a different kettle of fish. They cannot make major changes without your agreement. If they do they are in breach of employment law.
The company knows this and that is why my three days were returned to me as soon as I put pen to paper. Those of you that have voted yes to giving up your leave have now signed an agreement with the company which is personal to them. It has nothing to do with a vote.
The company is not stupid. They will have took advice from their lawyers before attempting to make major changes to your employment contract.