A schoolgirl inventor, who the Duke of Cambridge said “puts us all to shame”, has called on Cop26 to “stop talking and start doing”.

Vinisha Umashankar was a finalist in William’s Earthshot Prize and received praise for her solar-powered ironing cart, which aims to replace air-polluting charcoal clothes presses used by street vendors in her homeland India.

At a gathering of world leaders including Prime Minister Boris Johnson, his Indian counterpart Narendra Modi and US President Joe Biden, the 15-year-old entrepreneur said: “Please don’t back an economy built on fossil fuels, smoke and pollution.

“Please stop debating the old debates! We need a new vision for a new future.”

Later at a reception where the Earthshot Prize finalists and winners were introduced to the world leaders, US Special Presidential Envoy for Climate John Kerry offered the rising green inventor support.

The duke introduced Ms Umashankar and her follow finalists and winners to the delegates just a few weeks after prizes of £1 million were awarded to the winners to develop their innovative solutions to help repair the planet.

He called on the leaders “to create the conditions in which they can thrive, and their ideas can scale”.

During the day, William sat down for talks with billionaire Amazon founder Jeff Bezos and discussed the Earthshot Prize and scaling up the solutions of the winners and finalists.

The schoolgirl received a standing ovation after her speech which emphasised how she represented the generation which had much to lose.

She said: “The point is that me and my generation will live to see the consequences of your actions today. Yet none of what we discuss today is practical for me.

“You are deciding whether or not we’ve a chance to live in a habitable world. You are deciding whether or not we are worth fighting for; worth supporting and worth caring.”

Hammering home her message for the global heads of government to take action before it is too late, she added: “Many of my generation are angry at leaders who’ve made empty promises and failed to deliver.

“We’ve every reason to be angry. But I’ve no time for anger. I want to act. I’m not just a girl from India. I’m a girl from Earth. I’m very proud to be so. I’m a student, innovator, environmentalist and entrepreneur but most importantly, an optimist.”

The teenager’s solar-powered invention can power an iron for six hours from five hours of sunshine and it eliminates the 11 pounds of charcoal used daily by vendors, cutting pollution.

William praised the 15-year-old saying her innovation was “just one of her many inventions”, adding her hard work “puts us all to shame”.

Praising their “amazing ingenuity”, the Duke warned the audience, including Microsoft founder Bill Gates: “Our finalists are bursting with energy, ideas and ambition, so please expect many of them to come knocking on your doors!”

Before finishing, the schoolgirl said: “I invite you to stand with us. We hope that you would give up the old thinking, old ways and old habits. We extend our hands to you.

“But let me be clear! We won’t wait for you to act. We will lead even if you don’t. We will act even if you delay.”