Football team rivalries are often at the heart of banter in the workplace.
But fans can be legally denied jobs by a potential employer if current staff support a rival team, a judge has ruled.
Companies are allowed to base recruitment decisions on whether a prospective colleague might 'damage office harmony', Employment Judge Daniel Wright said.
As such, he said, the boss of a business would not break employment law if he rejected a job application from a Tottenham Hotspur season ticket holder because his office is full of Arsenal fans.
The decision may not be good for business, however, EJ Wright added.
The ruling case in the case of a Russian woman who sued after she lost out on a job with a marketing agency because she didn't 'vibe' with her interviewers as well as the successful candidate.
Maia Kalina claimed that she was discriminated against because she was not 'outgoing' and didn't enjoy going to the pub.
But EJ Wright dismissed her claims, saying employers had the right to consider whether a prospective employee would get on well with existing staff.
'There may be times when it is perfectly lawful for an employer to decide that somebody just will not be a fit with the team and that therefore it would be difficult to work together,' he said.
'An example of this could be a small company where everybody who works in the office is an ardent supporter of Arsenal Football Club, and they decide to pick an Arsenal fan at interview over a similarly qualified Tottenham Hotspur season ticket holder because they do not want to damage the harmony of the office.
'The decision there would be lawful (albeit taking the example to the extreme would not necessarily be good for business).'
The hearing in Croydon, south London, was told Ms Kalina applied for a role with Digitas LBI and got down to the final two but lost out to the other candidate.
Explaining her decision, interviewer Stephanie Hill told the tribunal that she 'vibed' more with the other applicant and that 'ultimately the decision came down to who was the better fit in the team'.
Mr Kalina - who suffers from depression - said her mental health issues mean she struggles to socialise and that her culture doesn't involve pub going or swearing.
EJ Wright dismissed her argument, however.
'In the present case we have two candidates who were both considered appointable. They were pretty evenly matched, with their own particular strengths.
'In that situation I see nothing wrong with looking at who would fit into the team better as long as the assessment is done with caution.
'In this case, [Ms Kalina] relies upon a stereotype of British people being outgoing, enjoying going to the pub, and being relaxed swearing whereas she is more restrained as she comes from a cultural background where going to the pub is not a big thing and swearing is frowned upon.
'I find that there is no stereotype of British workers being as [she] describes. I accept that a number of British people could be described as going to the pub, swearing liberally and being outgoing.
'But there are just as many British people who frown upon anything which could be considered a curse word, who eschew the pub culture and who are far from outgoing and instead have the British 'stiff upper lip'.
'As such, in the absence of evidence, I am not satisfied that this stereotype of British people exists because at best, it would apply to a sub-group of British people.
'[Ms Kalina] described it as an 'unspoken template of Britishness' but I reject that.
'I would be prepared to accept that there is a stereotype of people who work in marketing of being loud, swearing and having a drinking culture, but that does not assist [her] in her race discrimination claim.'
Dismissing her claims of race and disability discrimination, he said: '[Digitas] were entitled to chose between two good candidates on the basis of who would fit in with the team.'