You would only have grounds to claim constructive dismissal if you resigned, with or without giving notice, because of your employer's behaviour. It has to be shown that the employer's conduct is so serious that it amounts to a fundamental breach of conduct, which goes to the heart of the employment contract.
For claims based partly or completely on events before 6 April 2009 you also need to have brought a formal grievance against your employer and stated the reasons for your grievance.
Examples include:
