Piers Morgan has claimed he worries about Greta Thunberg “more than her supporters” and thinks the teenage climate campaigner is being used.

The Good Morning Britain presenter was responding to criticism on Twitter after he ridiculed the Swedish 16-year-old for attending a demonstration over global warming in Vancouver on Friday.

Morgan, who has previously performed a mocking impression of Thunberg on live TV, replied to photo the activist had posted: “Congrats. Looks like you’re having a lot of fun despite we ghastly adults ruining your childhood. Will you be reaching school again any time soon?”

The presenter was swiftly criticised for his sarcastic comment, which referenced a powerful speech Thunberg delivered at the UN in September in which she told world leaders: “You have stolen my dreams and my childhood with your empty words.”

One person accused Morgan of “hating on a child” while another said he was “picking” on Thunberg.

Greta Thunberg inspires climate activists everywhere: In pictures Show all 12 1 /12 Greta Thunberg inspires climate activists everywhere: In pictures Greta Thunberg inspires climate activists everywhere: In pictures In the protest that started a movement, Greta skips school to sit outside of the Swedish parliament in Stockholm in order to raise awareness of climate change on 28 August 2018 Getty Greta Thunberg inspires climate activists everywhere: In pictures Greta speaks at the World Economic Forum in Davos on 25 January AFP/Getty Greta Thunberg inspires climate activists everywhere: In pictures Greta stages a protest at the World Economic Forum in Davos on 25 January Reuters Greta Thunberg inspires climate activists everywhere: In pictures Greta speaks at the House of Commons in London on 23 April PA Greta Thunberg inspires climate activists everywhere: In pictures Greta addresses to the occupation at Marble Arch in London on 21 April AFP/Getty Greta Thunberg inspires climate activists everywhere: In pictures Greta meets the pope on a visit to Rome Reuters Greta Thunberg inspires climate activists everywhere: In pictures Greta speaks at the senate in Rome on 18 April Reuters Greta Thunberg inspires climate activists everywhere: In pictures Greta addresses a debate of the EU Environment, Public Health and Food Safety committee at the European Parliament in Strasbourg on 16 April AFP/Getty Greta Thunberg inspires climate activists everywhere: In pictures Greta receives the Special Climate Protection Award at the German Film and Television awards in Berlin on 30 March AFP/Getty Greta Thunberg inspires climate activists everywhere: In pictures Greta attends a children's climate protest in Berlin on 29 March AFP/Getty Greta Thunberg inspires climate activists everywhere: In pictures Greta addresses a children's climate protest on 1 March in Hamburg Getty Greta Thunberg inspires climate activists everywhere: In pictures Greta attends a meeting for the Civil Society For rEUnaissance at the EU Charlemagne Building in Brussels on 21 February AFP/Getty

Morgan later responded to the criticisms in another tweet, writing: “Oh, I don’t hate Greta at all.

"I find her passion admirable, albeit her rhetoric can be very hectoring and annoying.

“But I think she’s being used, and I worry about her more than her supporters seem to.”

Thunberg's emergence as one of the most recognisable faces in environmental activism has seen her come under attack from a range of prominent figures including US president Donald Trump and the owner of luxury fashion conglomerate Louis Vuitton Moet Hennesey.