Prince Harry and Meghan Markle's names have been banned from being used in front of King Charles ahead of his 75th birthday celebrations at Clarence House next week according to reports.

Sources have revealed that royal aides are so afraid of the “dreaded H or M” words spilling out in front of the monarch that they have quietly told members of the household to ensure they are not mentioned in his presence, the Express reports.

The source claims: “Not only will the King hold a lavish reception at Clarence House on November 14, but he will also make an appearance at a charity event at Highgrove a day earlier.

“It has been made very clear that Sussex discussions are firmly off the table at both events.”

The Prince's Foundation, which was established by the monarch in 1986, will host celebratory events at both Highgrove Gardens and Dumfries House in Scotland on November 13 for organisations and individuals also turning 75 this year.

The source added: “The foundation event was originally planned for Dumfries House, but the King was keen to have a secondary event placed upon his doorstep at Highgrove so that he could join in the celebrations".

According to the insider, if the event all goes well, with no illnesses or interruptions, King Charles will make an appearance at Highgrove.

Join the Daily Record's WhatsApp community here and get the latest news sent straight to your messages.

They said: “Although it hasn’t been officially confirmed just yet, the King has an appearance at Highgrove pencilled in his diary”.

November has been a busy month so far for both the King and his wife Queen Camilla as they have already made a State Visit to Kenya followed by the State Opening of Parliament on Tuesday November 7.

Remembrance Sunday falls on November 12, followed by the Highgrove and Clarence House events and a gun salute is scheduled in Green Park on November 15.

The source said: “The King has a busy few days between November 12 and 15. It will involve a lot of back and forth between London and Gloucestershire, but he’s determined to celebrate his 75th birthday without any interruptions.

"He doesn’t want the day to be overshadowed by people who aren’t there - the unmentionables as staff now call them.”

On top of all this, it was revealed at the beginning of this week that Prince Harry and Meghan Markle had in fact not been invited to the King's 75th birthday celebrations.

Sources say that the Sussexes' would normally have always been included in any large-scale family gatherings, despite the ongoing feud between themselves and the Royal Family.

The source continued: “All the senior members of the Royal Family are expected to make an appearance at Clarence House,” the source said.

“The fact that the Sussexes weren’t even invited to an important milestone like this speaks volumes. It will be very hard for them to claw their way back from this.”

Get the latest celebrity gossip and telly news sent straight to your inbox. Sign up to our daily Showbiz newsletter here.