POLICE changed an "Operation Bunter" codename for Boris Johnson's next trip to Scotland to avoid offending the Prime Minister, it has been reported.

The Scottish Sun said the name given to the security preparations was switched amid concerns it echoed the fictional overweight public schoolboy Billy Bunter. 

A source told the paper: “The name ‘Operation Bunter’ was given to the preparations.

“But several people pointed out the foolishness of calling it after a fat, posh English public schoolboy - not least given the PM is known for being a bit portly.”

They added: “Operation Aeration was selected as the alternative.

“But I’m not sure moving away from Billy Bunter to a name that implies the PM is full of air is much of an improvement.”

Billy Bunter was created by Charles Hamilton using the pen name Frank Richards, and featured in stories set in a fictional English public school called Greyfriars.

He was known for his greediness and overweight appearance.

Mr Johnson famously attended Eton College and has spoken of his efforts to lose weight.

Police codenames are auto-generated from a list of approved words.

The Prime Minister last visited Scotland in January. No date has been announced for his next trip north.

A Police Scotland spokesperson told the Scottish Sun: “Operational names are auto-generated by computer and can be changed if deemed to be inappropriate.”