Joanna Lumley "turned rather dim" when she met Queen Elizabeth for the first time

Speaking on 'The Andrew Marr Show', she said: “Even the people who say, ‘What an honour, oh you’ll love it, she’s so friendly’, no matter how much of that goes on you’re absolutely terrified the first time you see the Queen.

“It’s almost like an electric shock because somebody so familiar is suddenly in front of you.”

“When she looks at you her eyes are so blue and so you have that shock and you immediately start being rather dim and rather babbly.”

And the 'Absolutely Fabulous' star admitted she could "never" think of appropriate things to say to the queen and on one occasion she confided in her about her concerns about legalising drugs.

She said: “I went to one of the lunches at Buckingham Palace and for some extraordinary reason [when] she said, ‘Tell me what you’re doing nowadays’ I said I’m very concerned about legalising drugs.

“I mean what happened to me, as if she would care, she had no interest in it. Anyway she let me babble on for a little bit because she is very good at listening to people.”

Joanna previously praised the queen after it was reported the monarch had said she found it "irritating" when world leaders "talk but don't do" when it comes to taking action on climate change.

The actress said: “Isn’t that terrific? We’re much, much closer to disaster than we think and we want to see something happening now, not all these people rubbing their chins and having a committee meeting and presenting minutes and back-slapping.”