Can my boss retrospectively change my contract if I don't agree?

[Campervan69]

I've been off on a week's holiday and unfortunately I can access work emails from home. My boss has sent an email around the company which is a small family run firm stating that any financial errors made by fee earners (I work in a legal practice) will be deducted from the salary of the person responsible.

I immediately sent an email back stating that I do not accept this and I would not work under these conditions. Is he able to do this?

No. But I'd argue as a collective and as part of a Union not individually.

Contact Unite.

The trouble is that the only other fee earner is the boss's son and his two daughters are the admin so I'm not convinced that they they would be in any kind of position to fight against this because their father is very old fashioned and rules them under a climate of fear.