work conditions change

Recently have been asked to accept new work conditions which I havent accepted as more responsibility with no remuneration. I have been told by manager that I should leave if I dont accept this. Where do I stand as I dont think this person can act in this manner. I have asked for the terms and conditions and told that I should be happy to have a job in the current climate. Regardless of the economic climate I feel that employers have to treat their workers in a fair and responsible manner.
I am not accepting new conditions but need to figure out what is the best way forward.

What does your contract say? Mine says I can be redeployed with my consent. A couple of years ago they tried to move me and I objected. At the time I also joined a union and work backed down without me having to involve the union.

It's not uncommon in a lot of companies for an employer to do this. It can be seen as a developement opportunity to see if you are capable and suitable for promotion which if your not, the employer can move you back to your pre-existing role and if you are, you can then have a discussion at a later stage around salary. In the last 2 organisations I worked for (both American), salalry in a new role was reviewed 6-12 months after you had started in the role

Well you need to decide what you want for doing the extra they are asking, then negotiate with your employer. If they wont meet your demands then its up to you weather you stay or go, but the chances are you will not gain anything from going.