Can my employer leagally cut my wages and take away my holiday and vacation pay?
Unfortunately, they can almost certainly cut your wages. Generally speaking, unless there is an employement contract (including a union agreement) in place, employers have complete discretion as to what they pay employees and may cut wages at will. (They can also fire people at will.)
In terms of holiday or vacation pay, an employer can take it away going forward--i.e., for the future. They cannot, however, take away vacation or holiday pay that you've already earned; in other words, if you'd taken a vacation or had a holiday prior to the announcement, the employer still needs to pay you for it, though they can take away paid vacation or holidays in the future.
Most employment relationships are what is known as "at will". This means that basically the employer can hire or fire someone for any reason or no reason whatsoever, as well has increase/decrease salary/hours, promote/demote, and generally impose requirements and revoke benefits as they see fit. In turn, you can work for an employer, or not, your choice.
The only exceptions to the above would be if there is a stated company policy covering this, or there is a union/employment agreement that governs, or this situation has arisen due to some type of discrimination.
However, as to holiday that is already earned, since that is considered to be a part of your compensation, it cannot be taken away. Only holiday pay going foreword (ie in the future) may be taken.