A poster mocking the apparent age of child refugees has been found pinned up in the British Parliament.

UK Labour MP Chi Onwurah tweeted a picture of the poster, which was found sellotaped to a wall in a communal kitchen.

The poster, which shows an elderly man, is captioned: "Just £3 from you could clothe and feed this 12yr old Syrian child for a week".

Ms Onwurah tweeted: "Upset someone in Parliament thought it funny to display this in the communal kitchen over the weekend #refugeeswelcome."

The MP for Newcastle said she tweeted the image to shame those responsible, branding it "xenophobic".

"I think it demonises and dehumanises Syrian migrants - I think that is xenophobic," she said.

"To demonise and reduce people fleeing Syria, when we've seen what they are going through, to a meme basically saying they are liars and dishonest - I think it is offensive.

"I want to make sure it doesn't happen again and I want to make it clear that it isn't acceptable."

Upset someone in Parliament thought it funny to display this in the communal kitchen over the weekend. #refugeeswelcome pic.twitter.com/UJzTKy4we3

— chi onwurah (@ChiOnwurah) October 24, 2016

The poster was found by Ms Onwurah's researcher Sarah Pine, who said the kitchen serves 17 MPs from Labour, the SNP and the Conservative Party, as well as their staff.

It remains unclear who was responsible.

The discovery comes amid an ongoing row over the apparent ages of child refugees entering the UK from the Jungle refugee camp in Calais.

Several newspapers suggested refugees claiming to be minors were actually over 18, and Tory MP David Davies recommended they undergo dental checks to establish how old they are.

Critics, including former footballer Gary Lineker, condemned the suggestion, slamming the treatment of child refugees coming to the UK as "hideously racist".