Amendment To Employment Contract Employment Law - Is This Legal?

Employment Law - Is this Legal? - amendment to employment contract

I am one of about 80 officials of all the same in the contract of employment in a factory. Given the current global economic situation in our production staff (on another contract with an agreement had been planned initially) said they would lose 1 days work per week, the cost of production days. The company selected the 10 officials of the 80 "are associated production" and tried to follow us to 10 power and also the example and the same as the redundancy of the production staff to have.
We have not received anything in writing or had no change in our current contract, but basically telling us that we be released?
The company can legally discriminate against employees and 10 separate us from the rest of the 80 employees in the same order?