See ACAS leaflet page 5.

An alternative is for the employer to terminate all contracts and offer new ones (that in this case would not include company cars.), see page 6.

From the leaflet:

"An existing contract of employment can be varied only with the agreement of both parties" :smug:

and this element which others have mentioned albeit I hadn't appreciated:

"Where an imposed change involves a significant change to the contract, eg: a reduction in pay or alteration of working hours, an employer may well be acting in fundamental breach of contract. Where there is a fundamental breach, the employee may treat the breach as bringing the contract to an end and leave the job. In such circumstances and subject to having the necessary qualifying service, the employee will have the opportunity to make a claim of constructive dismissal before an employment tribunal."

If the change were significant then I'd (a) leave as it'd be an easy tribunal win (b) stay under protest & take it to a tribunal, leaving after I'd won.

TX.

Just to confirm, at the moment all I am losing is the option to take a car instead of the allowance I already get, they are not proposing that we lose the allowance.