Gill
the racist question aside for a moment. As far as I'm aware an employer isn't allowed to make major changes to an existing contract without consulting the other side, therefore they may be in breach of contract by changing the sick pay terms. They would have to offer redundancy pay to those who don't accept the new terms.
If they don't offer redundancy and either force employees to accept the new contract or sack them, there are grounds for unfair dismissal.
But things might have changed yet again....
Maybe DB74 will be able to help you with this.