Few of us relish the idea of enemies in the workplace and working out how to manage folk who've placed themselves in this category can be tricky.
But is ignoring the situation in the hope things will settle down over time the best bet? Or can you increase the odds of rehabilitating your relationship by taking a more proactive approach?
The latter, says Peoplebank senior manager Peter Kennedy, who's navigated and observed his share of difficult workplace relationships during a three-decade career in the IT and recruitment industries.
"It generally came down to egos," Kennedy says.
"Because our industry's quite territorial where you had responsibility for a certain patch, if someone stepped into that patch or you stepped into theirs, that's where relationships can get tested."
Can we talk?
While the prospect of a tete a tete can be intimidating, inviting the other party to meet on neutral ground to discuss your differences is the best way to begin the fence mending process.
"The worst thing is confronting someone in an office environment particularly when the other party is not ready," Kennedy says.
"Put some thought into it, plan it, what you're going to do … Ask them for a coffee or go in a room for a chat and then it's all about recognising what's happening, being quite straightforward with that other person to let them know how you feel – but you've got to put your ego away.
"I often find that the first five minutes can be a bit tense but once both parties have vented their anger, the mood of the talk can then settle down."
Look in the mirror
Taking a hard look at your own behaviour before you talk to the other party about theirs is vital, Peak Performance Psychology principal Jo Lukins says.
"The tendency that people have is to look outwards so they might say, 'Mary at work's been mean to me' or 'she's not getting along with me' or all those things," Lukins says. "The tendency can be to focus on that other person and I actually think you need to focus on yourself, to reflect on what you're doing.
"Say, 'What am I doing that's contributing to this, how am I not helping, what's my story that I'm telling myself as I engage with this person? Am I saying to myself, 'They're a villain' or 'I'm a victim' or 'This is hopeless'?'
"Obviously all that sort of self-talk gets in the way of effective relationships."
Everybody plays a part
Be prepared to accept that your actions may have contributed to the souring of relations and avoid playing the blame game if you want the initial conversation and subsequent interactions to be constructive, agrees workplace performance coach Michelle Gibbings.
"It really needs to be done with good intent, with real, genuine heart attached to the conversation: I'm really having this [chat] because you matter to me and something's gone wrong and I know that I've played a part in that," Gibbings says.
"It can't be: You've done this to me and you've done that. Often when relationships aren't working it's both parties; there's something on both sides that hasn't worked so you need to be prepared to accept your part."
"They hate me"
It's human nature to leap to the conclusion that the other party has it in for you but making an effort not to do so will stand you in good stead.
'When people are having a relationship with someone at work that they're struggling with, they'll assume the other person's intent towards them is negative… they assume it's because this person's trying to do something to me, trying to get some of my turf or they're trying to put me in a more difficult position," Gibbings says.
"If they have the courage, and it does take courage, to step into an uncomfortable conversation they'll often find that the other person has a completely different intent to what they have assumed the intent is."
Breaking the cycle
If the ill-will does seem to be personal, a no-strings act of kindness can sometimes be enough to turn sour relations sweet, mediator and trainer Naomi Holtring says.
Several years ago she took flowers to a colleague who'd helped make her life at the marketing company where the pair worked a misery, after the woman was hospitalised following a car accident.
"A few months later when she came out of hospital, she cornered me in the toilets and I thought, Oh, no, and she said, 'Naomi I'm really sorry, I don't know why I've been so horrible to you'," Holtring says.
"That was the culture of the organisation. Changing that was a matter of offering the olive branch; being nice to the person who was actually the nastiest to me."
Have you managed to rehabilitate a workplace relationship? Share your experience in the comments section below.