Hi, I'm a Retail Pharmacy Manager. I've been working for the business for 8 years and had no previous warnings. For more than 6 months, I've been experiencing work related stress, workplace bullying & harassment from the owner and 2 work colleagues. 5 days ago, I was told by the owner that I'm no longer suitable for my position; reasons were drop in sales, customer theft, other staff performance and for carers leave I had taken which I provided a certificate for. I've been off work since that afternoon on stress leave from the doctor. I feel I'm being targeted and I'm forced to resign as I physically and mentally can't take it anymore. Would this be grounds for unfair dismissal and can I hand in the letter while on stress leave?