A personal assistant who was forced out of her job because her boss told her he wanted ‘to trade her in for a younger model’ has won a claim for unfair dismissal at a tribunal.

Dawn Bailey claimed she felt she had to leave her job at defence giant Lockheed Martin in February 2012 after she developed the chronic illness sarcoidosis and depression shortly after turning 50.

Bailey was PA to Chief Executive Stephen Ball and informed the tribunal that he repeatedly poked fun at her age and said her illness was ‘disruptive’.

Having worked at the company for 19 years, Bailey said she resigned in February 2012 because it was ‘impossible’ for her to stay.

The Central London Employment Tribunal ruled that Miss Bailey had been wrongfully dismissed from her job and subjected to unfavourable treatment because she suffered from depression.

It said that the multi-billion pound company should have appreciated that she needed more “pastoral and human support” after she was diagnosed with depression and anxiety in November 2011.

The Tribunal found that Mr Ball had made the comment about wanting “a younger model” but accepted it was made as a joke, and rejected claim for age discrimination.

However, the tribunal found she had been unfairly treated because of her illness, which was equivalent to a “disability”.

The Tribunal heard that Miss Bailey had an “unblemished” career at Lockheed Martin, but her relations with Mr Ball began to decline towards the end of 2010, when she was diagnosed with the chronic illness.

Miss Bailey took several weeks off work during 2011, and the Tribunal found that in her absence her job was slimmed down and sidelined.

She accused Mr Ball of “intolerance of illness and seniority” after he made repeated reference to her age, and in December 2011 she was suspended on “management directed leave” and escorted from the company’s offices.

The Tribunal found that Miss Bailey was “marginalised” on her return to work after she took time off with her illness and was met with “cold-shouldering” instead of sympathy and support.

Following the hearing, Paul McAleavey, Miss Bailey’s Solicitor, said:

“We are really pleased with the ruling. Only 3% of discrimination claims that reach a tribunal are successful so to have arrived at that upper percentile is great. It is a weight of Miss Bailey’s mind.

“This was a woman in her fifties taking on a multi-national arms manufacturer and winning on the majority of her claims.”

He also said that she is considering appealing the ruling that she was not discriminated against because of her age.

The Tribunal will decide next month how much compensation Miss Bailey will be awarded.