It all began when Tom questioned why The Wanted's Tom questioned why One Direction keep mentioning them on stage during their current Take Me Home tour.
"@Louis_Tomlinson you even talk about us at your own gigs. Are you that upset you didn't get in this band?" he wrote.
This led Louis to tweet Tom to mock his failed 'X Factor' audition, posting a link to a story about it.
"Uh oh . @tomthewanted The Wanted's Tom Parker: My failed X Factor audition shattered me," he wrote.
Tom fought back, tweeting a link to Louis' first audition: "Yes @Louis_Tomlinson, I don't need to call producers to beg my way on to a track over my "friends" #crybaby #loyalty#louisgottalent"
Louis then tweeted: "@TomTheWanted Pal, we both know I wouldn't waste my time auditioning for your band. You humour me with your bad boy persona."
He went on:"@TomTheWanted why don't we make your next single our movie soundtrack ?" to which Tom replied: "Hmm @Louis_Tomlinson I'd love to make the soundtrack to Mean Girls 3"
"@TomTheWanted P.S enjoy the press from this," Louis wrote.
"@Louis_Tomlinson I'll enjoy the press even more when you come clean #narnia #itgetsbetter," wrote Tom.
Louis then wrote: "@TomTheWanted Interesting you have to entertain your many followers with lies. I actually think you could be the biggest t**t on twitter."
Both have since deleted all their tweets.
Louis' bandmate Liam Payne also waded into the war, making a jibe at Tom's vocal ability.
"hey Tom lets (sic) talk about your singing, your amazing tone pierces my ears with every note :/," he tweeted.
Fellow The Wanted star Jay McGuiness jumped to Tom's defence, posting a longer statement about Louis, branding him 'overrated', 'arrogant' and 'insincere'.
"Dear @Louis_Tomlinson, please stop mentioning us in your gigs, we certainly no longer mention you and it's time to let dead dogs lie," he wrote.
"Your passive-aggressive style of speaking makes me cringe, and I wish you'd either have the b*llocks of some of your co-workers to speak truthfully, or the class of the majority of them to be silent.
"I'm not sure what's happened since we saw you at 'The X Factor', but you've done a sterling job of becoming one of the most overrated, arrogant and not to mention insincere people around.
"Your shocking lack of talent will only be forgiven by lots of humility and no-strings-attached friendship among your band. Louis, don't measure your worth in followers or money, because they're fickle, and when they go you might just feel worthless."
Louis has yet to respond directly on Jay's comments, simply tweeting: "Huge love to all our fans!! What a fun filled night haha !"
We have a feeling this one isn't quite finished yet...