The Scottish Secretary said he was disgusted at the controversial remarks directed towards MP Angela Rayner, deputy leader of the Labour Party, from a Conservative MP.
The shocking comments – published anonymously in a Sunday newspaper – accused Rayner of crossing and uncrossing her legs like actress Sharon Stone in the movie Basic Instinct to distract the Prime Minister Boris Johnson.
The article has also been heavily criticised for “classism” after referring to Ms Rayner’s teenage pregnancy, and becoming a social care worker with no qualifications.
Mr Jack said: “I think that any form of sexism should be called out. The remarks that were anonymously made were disgraceful, and frankly these are cowards who make these types of remarks anonymously.
“The Prime Minister has been very clear and messaged Angela Rayner directly and said ‘this is not in my name’.
“That’s absolutely right. I don’t know who said it and I don’t think we’ll discover who said it because I fear the journalist will respect his source’s anonymity and confidentiality.
“In this case I think that’s unfortunate because whoever said it should be called out for whatever punishment is available through the systems that exist within Westminster.”