Make sure you follow any internal grievance procedure before you resign
Whatever the problems you are facing at work, you should try and use the internal grievance procedure to resolve things before taking the step of resigning. However, this does depend upon the circumstances of your situation.
Don’t leave it too long before you resign
If you stay in your job for too long after your employer has breached the contract, your employer will try and argue that the breach wasn’t that bad, or that even if it was that bad, you have ‘accepted’ it by staying in work.
Make it clear in your resignation letter that you are resigning because of the breach of contract by your employer
Include the details of what has happened and the efforts you have made to resolve the situation, including the grievance process. Make it very clear that this is why you are resigning. The letter of resignation is a very important document and it is advisable to seek employment law advice on the contents of the letter.
Don’t leave it too long to seek legal advice
Remember that you only have a limited period of time to bring a constructive dismissal claim in an Employment Tribunal – usually 3 months less one day from the date you resigned, plus any extension of time due to ACAS Early Conciliation. You would be able to bring a wrongful dismissal claim (i.e. a claim for your notice pay) in a County Court and for this you would usually have six years in which to issue court proceedings.