The approach you've described refers to an individual organizations policy as opposed to the law.

Where the data protection act in the UK is concerned, a company is not required to release information on an employee if that information is stating an 'opinion' as opposed to a 'fact' about said employee. The problem is it's very difficult to state concrete, objective facts about an individual without the threat that it could be seen as a subjective opinion. This explains why many UK based companies will not give particularly detailed references and can easily hide behind the data protection act should they wish to do so. In fact many medium to large UK based companies will only give references through the HR department (not your direct line manager) and will only state concrete facts e.g. the length of time you worked there and primary responsibilities.

It has been my experience that to get a full reference from a line manager in such an environment then you need to have a good working relationship with that manager. By giving you a reference, the manager would be putting their own neck on the line i.e. the former employee could take legal action against the referee if they stated in their reference an opinion of the employee that the employee felt had an adverse effect on them getting a new job. These kind of cases are not uncommon and again it explains why companies very often refuse to give anything but the bare minimum when providing a reference.

As 'been there done that' stated in his post, why should a manager/company go the extra mile for an employee that they did not have a good relationship with? If we believe what was written about the OP (sparrow) he signed a new contract, then promptly left 3 weeks into it! That's hardly going to endear yourself to your employers is it?