Extinction Rebellion leave camp to march on Parliament Square

Demonstrators carrying flags and banners marched to drums and chants as they set off shortly after 10am.

Activist Jay Monk, 49, said it was a signal of a "renewed push" to have politicians answer the group's demands and inject fresh energy into the protests.

Protester Steve Jones, 53, suggested some of the disruption may be relaxed if the group was granted "meaningful discussions" with Government.

Several people accused of public order offences over the Extinction Rebellion climate change protests are scheduled to appear at Westminster Magistrates' Court today.

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Philip McMaster, bearded and wearing red robes as part of a character he calls "Sustaina Claus", called on politicians to engage with Extinction Rebellion.

The Canadian former teacher said: "We have given authority to them. That is why they are in power.

"Now they need to act for the best interests of our children."

Student Jade Edwards, from Worcestershire, said it was "brilliant" that party leaders might meet Greta Thunberg later today. The 16-year-old activist from Sweden is giving a speech at a meeting in Portcullis House at around 2pm.

She said: "If they listen to her that's a great step forward for the planet and everything that lives in it."

Theresa May was "empty chaired" as Swedish environmental protester Greta Thunberg met Westminster party leaders for a round-table discussion in the House of Commons.

Miss Thunberg met Labour leader Jeremy Corbyn, Liberal Democrat Sir Vince Cable, Green MP Caroline Lucas and the Westminster leaders of the Scottish National Party and Plaid Cymru, Ian Blackford and Liz Saville Roberts.

A place at the table was left free for May, with a sign bearing her name, but she did not attend. The Prime Minister was instead chairing Cabinet in 10 Downing Street.

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Organisers of Miss Thunberg's event said that no response had been received to their invitation to the Prime Minister, but they were still hopeful she might attend at least part of the discussion.

Opening the talks, Miss Thunberg - who earlier met Commons Speaker John Bercow - told the MPs: "We just want people to listen to the science."

Caroline Lucas told Miss Thunberg: "I hope this will be the beginning of an ongoing dialogue with young people.

"I think all of us are really committed to trying to ensure that there's an ongoing way to really make sure that all of our policies and all of our work in Parliament is properly scrutinised by young people with a perspective on climate in particular.

"We want young people's voices to be heard in Parliament. This is such an important moment, when the Inter-Governmental Panel on Climate Change say we have just 11 years left to get off the collision course we are on for climate catastrophe.

"That sense of urgency is here as never before, at a time when there have been protests on the streets not just of London but around the country and all the different nations of the UK. More than ever, politicians have our ears open to your message."

Jeremy Corbyn told Miss Thunberg: "Well done for what you have done."

Labour MP Clive Lewis told the crowd it had been "absolutely amazing" watching the protests over the past week.

He said: "You've put the climate crisis on the mainstream political agenda. They're even going to be talking about it in there (Parliament) because of you.

"This requires systemic change.

"It's not just tomorrow's generation who are losing their future. There are people now in the developing world for who climate change is a real impact here and now.

"Your struggle is our struggle.

"I don't want you to break the law.

"I want to change the laws in there (Parliament) which mean the people that kill and pollute this planet, they are the ones that should go to prison, not you."

Swedish schoolgirl climate change activist Greta Thunberg told a packed room in the Palace of Westminster 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.

"It was stolen from us every time you said 'the sky is the limit'."

Experiencing microphone problems, Miss Thunberg asked: "Is this microphone on? Can anybody hear me? Is my English okay? I am starting to wonder."

She added: "The basic problem is the same everywhere and the basic problem is that nothing is being done...

"You don't listen to the science because you are only interested in the answers that will allow you to carry on as if nothing has happened."

Labour leader Jeremy Corbyn tweeted an image of himself and Miss Thunberg in front of a portrait of Tony Benn.

He wrote: "It was a pleasure welcoming UK youth climate strikers and @GretaThunberg to parliament. Young people will be the most affected by climate change - seeing them take charge of their future is inspiring. Labour's committed to working with young people campaigning to save our planet."

Environment Secretary Michael Gove told Miss Thunberg she had been heard and admitted "we have not done nearly enough".

Speaking at the climate change event, he added: "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."

When asked what she would say to US President Donald Trump, Miss Thunberg said there was nothing she could say as he would not listen.

She said: "If I were to speak to Donald Trump today I don't think there is much I could say to make him change his mind.

"Obviously he must have scientists coming to talk to him all the time, so he is obviously not listening to the scientists.

"There is nothing I could say."