Boris Johnson has been accused of using sexist language by the Commons Speaker John Bercow.
The Foreign Secretary called Emily Thornberry, the shadow foreign secretary, Lady Nugee, the BBC reported.
The Labour MP’s husband is Sir Christopher Nugee, a high court judge, however she still uses her maiden name.
Bercow slammed Johnson as being "inappropriate and sexist" by using the name Lady Nugee and pointed out that MPs should only be referred to by their names and never their partner’s titles.
"I'm not having it in this chamber. No matter how senior a member... that parlance is not legitimate. It will not be allowed and it will be called out,” he said.
This resulted in the Conservative MP apologising for "inadvertent sexism."
This is not the first time Thornberry has been called Lady Nugee in the Commons.
Last year Theresa May referred to her in this way and this resulted in Thornberry complaining to Bercow about the matter.
She said: "I have never been a Lady and it will be a great deal more than being married to a Knight of the Realm in order to make me one."
May apologised for this, although she added: "I have to say to her, though, that for the last 36 years I have been referred to by my husband's name."