A UKIP politician has been slammed for a Twitter attack on 16-year-old eco-activist Greta Thunberg - after posting an image of her with demon eyes.

Neil Hamilton, 70, took to social media on Wednesday to mock the young campaigner as temperatures across the country soared.

He said: 'It's shaping up to be the hottest day of the year - please remember: No electric fans. DEFINITELY no air conditioning. Greta has spoken. #ClimateHoax #Extinction Rebellion.'

The Welsh Assembly Member included in his post an image of Greta Thunberg with fiery demon eyes - prompting strong criticism from Sally Holland, the Children's Commissioner for Wales.

Neil Hamilton (pictured), 70, took to social media on Wednesday to mock the young campaigner as temperatures across the country soared

Mr Hamilton included in his post an image of Greta Thunberg with fiery demon eyes - prompting strong criticism from Sally Holland, the Children's Commissioner for Wales

She said: 'I am mortified that a politician in Wales would make a personal attack on a child on social media in this manner.

'I have written to Mr Hamilton today expressing my disappointment in his failure to uphold high standards of public conduct.'

The young schoolgirl rose to public attention last August after she stood outside the Swedish parliament in a solo protest.

It prompted thousands of schoolchildren to walk out of classes in climate demonstrations around the world.

She has been credited with shifting the global outlook on environmental issues since she began campaigning last year.

Others to slam Mr Hamilton for his attack on the teenager included writer Lisa Holdsworth, who said: 'Is bullying and demonising teenage girls UKIP policy now?

'Or is it just proof that you can't engage with her on the facts and overwhelming evidence of the climate emergency?'

While psychiatrist Dr Benjamin Janaway said: 'Demonizing a young girl who is acting more responsible than you. Very UKIP.'

Responding to the criticism, Mr Hamilton, who is AM for the Mid and West Wales region, told the BBC that Greta Thunberg had 'very publicly entered the adult realm of political controversy'.

'If cabinet ministers such as Michael Gove take the opinions of this 16-year-old seriously then public criticism of her should be fair game,' he said.

'Miss Thunberg is currently pushing for policies estimated to cost the UK taxpayer £1 trillion which will hit the poorest the hardest.'

Greta Thunberg addresses lawmakers in the French parliament this week, but it was snubbed by some far-right politicians who mocked the 16-year-old activist

The Swedish campaigner arrives at the National Assembly in Paris with French lawmakers who invited her to speak

The incident comes after the teen activist hit back at French lawmakers after her speech in Parliament was snubbed by right-wing politicians who called her 'the Justin Bieber of ecology'.

Members of the Republican and National Rally parties boycotted the eco-activist's plea for lawmakers to swing behind her climate campaign and instead branded her a doomsayer.

Guillaume Larrive, of the conservative Republicans, described her as an 'apocalyptic guru'.

And National Rally lawmaker Sébastien Chenu made a swipe at the teenager's age by comparing her to singer Bieber, who shot to fame as a child.

But during her address to the lower chamber of the National Assembly in Paris, Thunberg scolded her critics.

She said: 'Some people have chosen not to come here today. some people have chosen not to listen to us.

'And that is fine, we are after all just children. You do not have to listen to us.

'But you do have to listen to the united science, the scientists. And that is all we ask. Unite behind the science.'

On Sunday, Thunberg was awarded France's freedom prize for her environmental activism which inspired a series school strikes that saw children walk out of class and protest on the streets.

French politicians invited her and other children into the country's parliament this weekto meet with MPs and discuss the so-called climate emergency.