LONDON, April 23 — Teen climate activist Greta Thunberg met a cross-party group of British MPs today including opposition leader Jeremy Corbyn, as environmental protesters staged a ninth day of demonstrations in London.

The Swedish activist, who is due to address the protests in Westminster later today, met Corbyn along with Liberal Democrat leader Vince Cable, Green Party MP Caroline Lucas and others in parliament.

"We just want people to listen to the science,” the 16-year-old told those assembled for a roundtable discussion on climate change.

Organisers of the meeting pointedly left a place empty for Prime Minister Theresa May, who was reportedly invited but chairing a cabinet meeting in Downing Street at the time.

They said there was no response to their invitation. May’s official spokesman said he was "not aware” of the request.

The UK Student Climate Network, an environmentalist group, said the meeting with the Westminster leaders had seen an agreement reached "on some important first steps they can take together to tackle the climate crisis.”

"We need to keep pressure up to ensure actions, not just words,” it said on Twitter.

Thunberg has inspired tens of thousands of children worldwide to boycott classes to draw attention to climate change after starting a solitary solo protest last year.

Meanwhile she has been visiting European capitals pressing for politicians to take the issue more seriously.

Thunberg travelled to Britain over the weekend to support fellow activists who have been causing gridlock in parts of central London since last Monday with sit-in protests.

Addressing the ongoing demonstrations organised by the Extinction Rebellion group on Sunday, she declared: "the struggle has barely begun. It’s only the beginning.”

Today, protesters carrying flags and banners marched to drums and chants from their makeshift camp at Marble Arch in central London to rally outside parliament on the first day MPs are back after an Easter break.

Police have arrested more than a thousand activists since they began their protests last week, and today announced 71 people will face charges over their actions. — AFP