Footage has emerged of Scottish National Party (SNP) MP Mhairi Black appearing to mouth “you talk s***e hen” to a Conservative minister.

The 22-year-old delivered an impassioned speech that criticised a Government proposal to withdraw housing benefits for 18-21-year-olds.

But Caroline Nokes, the Under Secretary of State in the Department for Work and Pensions, defended the Government action, eliciting an unusual response from the Scottish politician.

“The Scottish Government already has a wide range of powers which would enable them to alleviate the changes being proposed here,” Ms Nokes said.

Ms Black, who at 22 is the youngest member of the House of Commons, can then be seen shaking her head and muttering under her breath what appears to be the phrase: “You talk s***e hen.”

Social media users were quick to speculate on what she actually said.

Katie McGarvery tweeted: “No much of a lip-reader but definitely mouthing, ”you talk s***e, hen“.

It’s not the first time the Paisley and Renfrewshire MP has gone viral on social media.