A parliamentary aide and former partner of a Labour MP has won her claim for unfair dismissal at an Employment Tribunal after being “isolated and marginalised” for a year before she was sacked.

Elaina Cohen won two claims against former boss Khalid Mahmood after she was dismissed, but lost her claims that she was sacked on grounds related to race, religion or belief.

Mahmood is an MP for Birmingham Perry Barr and claimed Cohen was dismissed for breaking protocols of parliamentary office. He claimed Cohen had sent him “derogatory” and “offensive” emails, in which she referred to Mahmood as a “first-class idiot”.

Cohen began to work in Mahmood’s office in 2003 and the pair entered into a romantic relationship “in the early days”. It was reported Cohen’s and Mahmood’s relationship was “dysfunctional for many years”.

There was an afternoon, the court heard, in which Cohen and Mahmood spent arguing over an email exchange, which Mahmood then forwarded to leader of the Labour party, Sir Keir Starmer.

One month after this took place, Mahmood received another insensitive email from Cohen after his father-in-law passed away. Cohen emailed him again with “inappropriate and unnecessary” comments, referring to Mahmood as a “cold-hearted liar”, “jealous” and a “womanising con merchant”.

A panel led by Judge Tim Adkin ruled “this was in short something akin to a ‘poison pen’ email, calculated to be offensive to the respondent”.

January 2021 saw a formal disciplinary case launched by Mahmood, presenting five allegations against Cohen. On 27 January of that year, Cohen was dismissed from office.

The judging panel agreed that three of the five allegations made by Mahmood were “ample reasonable grounds for belief in misconduct”, but argued that the way Cohen’s dismissal was handled was “outside of the range of reasonable responses”.

A Tribunal spokesperson said:

“The Tribunal accepts the claimant’s evidence that she did feel marginalised and isolated from January 2020 until her dismissal. We find that the respondent, who had in recent years been in a fairly dysfunctional relationship with the claimant, offered very little by way of contact or support during the course of 2020. This was potentially detrimental treatment.”

Mahmood said he was pleased with the judgment demonstrating Cohen’s principal reason for dismissal was her parliamentary office conduct.

Employers have the right to dismiss an employee for misconduct that occurs in the workplace or even outside the workplace if it can be shown there is a link between the misconduct and the employer, its operational requirements and the location of occurrence in the context of the working relationship.

A remedy hearing is expected to take place on 29 and 30 September.