From totaljobs.com/careers-advice … rences-faq
Can my employer give me a bad reference?
Yes and no. Many people mistakenly believe that your boss can’t give you a bad reference by law, but that’s not entirely true…
References just have to be accurate and truthful so if you were disciplined at your last job then they could include that on your reference. However, many employers are scared to give bad references because anything considered to be not 100% accurate could be grounds for legal action. If you find out that you have been unfairly given a bad reference then you could possibly sue.
When I worked for the NHS the rule was that HR would only state the dates of employment and if there had been any formal disciplinary actions.