Boris Johnson's mother says he is interested in becoming the next Conservative leader.
And Charlotte Johnson Wahl said she was "anxious" about the Mayor of London taking the top job.
The 73-year-old told the Radio Times she was worried "about what the hell" her son is "going to do next" and admitted she has never voted Tory.
"He is interested in the leadership of the Conservative Party, but he could equally well retire and become a painter," she said.
"He's a very good painter. If he reaches the top, I'd feel very proud, but very anxious. It's a ghastly job being prime minister."
Meanwhile, Mrs Johnson Wahl also said her son, the MP for Uxbridge and South Ruislip, is "not as daft as he behaves", adding that Mr Johnson "does behave in quite a daft way".
He has a "very good sense of what's important" and would make a "good prime minister", she said.
Mr Johnson has previously said being prime minister would be a "great, great thing to have a crack at".
Mrs Johnson Wahl also commented on the possibility of Mr Johnson one day facing off against Jeremy Corbyn, the newly-elected leader of the Labour Party.
She said they would "understand each other quite well" but would disagree on "a lot of areas".
In the interview Mrs Johnson Wahl, an artist, also detailed her struggle with phobias and obsessive compulsive disorder.
Her anxiety around cleanliness made things "awful for the children" and she was admitted to a psychiatric hospital in February 1974.