Can you opt-out of new trading hours being introduced by employer?
Assuming you have a contract which states your current hours then your employer is trying to vary the terms of your contract which can only be done by mutual agreement. However this may be covered in Your contract by a flexibility clause. If there is no flexibility clause then you don’t have to agree to the change in terms of your contract, however, the employer would be within their rights to terminate the contract by giving you notice and offering you a new contract with the revised terms. Have a look at www.direct.gov.uk for more information about the above. In the employment section select employment terms and conditions, then contracts and conditions.