Yes, provided that the job offer is conditional on receipt of satisfactory references, the employer can withdraw the offer if it receives a poor reference, without this amounting to a breach of contract. Make sure that your offer letter includes the statement that your offer of employment is conditional upon the receipt of satisfactory references or any other requirements you may have such as the right to work in the UK, a satisfactory pre-employment health questionnaire, or a clean driving licence.
An employer that receives a poor reference may wish to investigate the situation further to satisfy itself that the individual is unsuitable and that it does not wish to employ them. If the employer decides to go ahead with the employment, it can make it clear to the employee that continued employment is subject to the satisfactory.
