I am quite sure you have a right to see the references under the Data Protection Act. I am also pretty sure you can sue the referee if the reference is factually incorrect.
References from former employers in the UK these days are vague and carefully worded because they don't want to be sued!
But to be honest, I would imagine the withdrawal of the job offer is more likely a result of commercial rather than personal considerations, and the 'poor reference' excuse merely a smokescreen.
Seek legal advice.