It seems like Scott Morrison will never live down a rumour about an incident in a McDonald's nearly 25 years ago.

Someone has decided to erect a plaque outside the Engadine Macca's in Sydney's south to pay tribute to the Prime Minister.

Posted on Reddit, the small memorial plaque says: "It was at this spot in the evening of 20th September 1997 that Scott Morrison defecated in his pants after the Cronulla Sharks lost the Super League Grand Final to the Brisbane Broncos 26-8."