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There’s nothing like an angry note from a neighbour to really rile you up.

But one woman’s Facebook rant after discovering the couple next door had left her a letter has sparked a furious divide over who is in the wrong.

The Sydney woman took to an inner-west mums group to reveal she was “fuming” after finding a handwritten scrawl from the couple next door asking her to help them “get more sleep”.

It seems Jackie and John had been struggling with the “thinness of the walls” between their units since the woman welcomed a new baby — and things had reached breaking point.

“We just wanted to let you know that unfortunately we’ve had a number of disturbed nights sleep recently due to the thinness of the walls between our units,” the note read.

“We don’t have children and are sure it’s not all easy to soothe a crying baby but we really would appreciate anything you can do to help us get more sleep, particularly in the early hours.

The message went on to thank the mum for her “consideration”, adding the couple looked forward to everyone involved getting “more undisturbed nights sleep” and signing off with the names “Janet and John” and their unit number.

After finding the letter, the mum shared it in a mothers’ group, writing: “So I just got this in my mailbox..... fuming!!! Do I respond with a letter? Leave it? Post earplugs in their mailbox?”

But while she may have hoped to receive support from her fellow mums, many empathised with the couple who had written the letter.

“That is a lovely note. They are just trying to come to an agreement with you. They also owned it by saying who it was from,” one said.

“I don’t reckon Jackie and John would appreciate their very polite and reasonable note being published on social media,” another said. “Not a great recipe for neighbourly relations.”

“I think it’s an incredibly polite letter that I’m sure was not easy to write,” one reasoned.

Someone else suggested the mum should be “more empathetic” of her neighbours.

But there were many who agreed with the mum that the letter was unreasonable, blasting the neighbours for hiding behind a piece of paper.

“Send them some earplugs or knock on their door the next time the baby cries and ask for help,” one said.

“Ask them to help pay for a sleep consultant,” another wrote.

In just a matter of hours the post sparked more than 500 comments, many of which sided with the neighbours, and the post has since been deleted.