Jeremy Corbyn's brother today branded environmental activist Greta Thunberg an 'ignorant brainwashed child' who is being 'abused by manipulative adults'.

Piers Corbyn, 72, a climate change denier who runs forecasting firm WeatherAction, said the 16-year-old who is visiting Britain from her native Sweden is 'wrong'.

Reposting a BBC News article titled 'Teen tells UK politicians 'listen to climate scientists', he tweeted: 'Listening to an ignorant brainwashed child is deranged.

'I am an actual scientist of physics, meteorology, astrophysics and climate and say Greta Thunberg is wrong and suffers mental abuse by manipulative adults.'

Piers Corbyn, the brother of Jeremy Corbyn, protests against climate change activists as people queue to see Greta Thurnberg speak on Euston Road in London on Easter Monday

Piers labelled Greta an 'ignorant brainwashed child' being 'abused by manipulative adults'

It comes a week after Piers called protestors who glued themselves to his brother’s house 'deranged', as he staged a counter-protest at the Waterloo Bridge occupation.

The meterologist, whose office is in South London, waved one banner denouncing global warming as a 'hoax' and another calling carbon dioxide a 'gas of life'.

Piers, who is the Labour leader's older brother, believes that accepted science on man made climate change is a 'cover up' that exists to push up fuel prices.

Condemning the protests, he added last Friday: 'This is disrupting traffic and stopping people going to work, the police should have moved them on ages ago.'

Piers runs WeatherAction, which has been questioned for its unusual methods of forecasting patterns, but he is adamant that man-made climate change is a hoax.

Yesterday, Labour leader Jeremy, 69, met with Greta, who is visiting the UK to express her support for the ongoing Extinction Rebellion protests in London.

Greta meets Green Party leader Caroline Lucas (left) and Labour leader Jeremy Corbyn (right), at the House of Commons in Westminster yesterday

Mr Corbyn posted this tweet after meeting Greta at the Houses of Parliament yesterday

Jeremy described the meeting as 'absolutely fascinating', saying they had discussed issues around pollution, emissions and agriculture.

'We agreed that we would continue those discussions when we put forward policy so that we are measuring our policy against the environmental impact,' he said.

Greta at the House of Commons yesterday

'We have to have a much more focused and serious approach towards climate change and the damage we are doing to our natural world.'

The Swedish Nobel Peace Prize nominee has sparked a wave of youth climate protests around the world and yesterday met political leaders in the Commons.

She told a politician's roundtable: 'We just want people to listen to the science.'

Greta also met Liberal Democrat leader Sir Vince Cable, Caroline Lucas from the Green Party and the Westminster leaders of the Scottish National Party and Plaid Cymru, Ian Blackford and Liz Saville Roberts.

Prime Minister Theresa May was 'empty-chaired' at the meeting as she was attending Cabinet at the time.

Speaking at an event in the Palace of Westminster, Miss Thunberg later said her future and those of her fellow children had been 'sold'.

She said: 'We probably don't even have a future any more. That future has been sold so that a small number of people can make unimaginable amounts of money.'

Environment Secretary Michael Gove (left) and former Labour leader Ed Miliband (second right) are among those listening to Greta (right) at the House of Commons yesterday

Greta speaks at the Houses of Parliament yesterday as Extinction Rebellion protests continue

Greta posted a picture this morning of her catching a Deutsche Bahn train home from Brussels

Environment Secretary Michael Gove told Greta she had been heard and admitted 'we have not done nearly enough'.

Greta addresses the Extinction Rebellion demonstrators at Marble Arch on Sunday

He said: 'Suddenly in the past few years it has become inescapable that we have to act. The time to act is now, the challenge could not be clearer, Greta you have been heard.'

Shadow Home Secretary Diane Abbott tweeted that Greta gave a 'great speech' and was 'showing adults the way forward'.

She added that the activist's climate change message is 'so powerful and important for all our futures, and especially for the youngest generations.'

XR is urging the Government to declare a climate emergency to avoid what it calls the 'sixth mass extinction' of species on earth.

Dozens of police officers lined the fringes of the Parliament Square demonstration yesterday - with Scotland Yard earlier saying it had a 'robust' policing plan in place.

Greta poses for a photo at the Extinction Rebellion camp at Marble Arch in London on Sunday

Extinction Rebellion demonstrators listen to Greta speak at Marble Arch in London on Sunday

Piers Corbyn (right) takes part in a tiny counter-protest at Waterloo Bridge on Good Friday

More than 1,000 people have been arrested during XR protests which started on April 15, while more than 10,000 police officers have been deployed.

XR action has seen Waterloo Bridge and Oxford Circus blocked and a 'die in' at the Natural History Museum.

Elsewhere, activists have glued themselves to trains, chained themselves to objects, and some could even be seen perching in hammocks up trees overlooking Parliament Square.

Members of XR have previously indicated temporarily ending disruptive tactics to focus on political negotiations.