As soon as you have been offered a job, and have accepted it, this forms a basic legal contract between you and your new employer, even if you haven't yet received anything in writing. Often job offers are expressed to be subject to receipt of “satisfactory” references. However, if the prospective employer doesn't mention this at the time, it can't add this condition later on.
If an offer that has been accepted is then withdrawn, your employer has 'breached' the contract. It may be possible for you to sue your new employer as a result, particularly if you have suffered loss because you have left your previous job to take up the new offer.
If a court decides that your contract was breached, it can order your employer to pay you 'damages' or compensation.
