The firm we worked for lost the cleaning contract for a building in the town centre, so we now work for the firm that took over. This firm’s employees all get 31 days’ paid leave, while we only get 28. Is that legal?
It sounds as though you are receiving the statutory minimum holiday allowance. Generally speaking your new employers aren’t obliged to offer you the same terms and conditions as staff already working there as long as they honour the contract you had with your previous firm. You will have to press for any improvements that might put you on a par with your co-workers. Talk to your union rep if you have one.