She is alleged to have told Prince William personally about the decision to prevent her from using the iconic pieces of jewellery.
Sources close to the Royal family claim Her Majesty made the remove in response to some of Meghan’s behaviour in recent months.
“Aspects of Meghan’s behaviour — including before the Royal Wedding — caused resentment with forces within Buckingham Palace,” a royal source told The Sun.
They went on: “This is a surprising situation that has been going on behind the scenes over the past few months and has caused tension and upset, especially for Harry.”
The source explained: “It is at the discretion of the Queen and trusted advisers which items in the Royal Collection she chooses to loan out and to whom.”
They added that “the Queen herself was not impressed with some of Meghan’s demands, especially as a new member of the family.
“As a result, Buckingham Palace has decided that not all items from the Queen’s royal collection will be opened up to Meghan.”
This is believed to include all the items previously worn by Princess Diana.
The source insisted: “The Queen likes Meghan personally but this is about the hierarchy.”
And they added: “Even if Meghan is the most popular woman in the world, she is of a lower rank than Kate.”
It comes after the Duchess of Sussex was reportedly stopped from wearing an emerald tiara at her wedding last May, leading Harry to insist: “What Meghan wants Meghan gets”.
Sources close to the new royal described Meghan as “difficult” with “high standards” because she was more used to “a Hollywood environment”.
The row comes just weeks before the couple is due to give birth to their first child.
On Wednesday, Daily Star Online reported Meghan Markle may not pose at hospital with her baby because of her “feminist world view”.