The 18-year-old, who has become a poster girl in the fight for greater action to tackle climate change, has said the international summit should be postponed. The Swedish activist said the global pandemic and a shortage of vaccines worldwide meant the conference could not go ahead as planned.
While Ms Thunberg was not set to be given any formal role at the conference, her approval would have helped raise the profile of the summit.
Her decision not to attend will be a symbolic setback for the Prime Minister, who is hoping to use COP26 to cement Britain’s position as a world leader on green issues.
Mr Johnson believes battling climate change is one of the areas in which Britain can forge a new global role for itself post-Brexit.
The issue is also a priority for US President Joe Biden, with the UK hoping to use COP26 to revitalise the relationship with Washington as it seeks to secure a trade deal.
Announcing she would not be attending on social media, Ms Thunberg said: “Of course I would love to attend the Glasgow COP26 but not unless everyone can take part on the same terms.
“Right now many countries are vaccinating healthy young people, often at the expense of risk groups and front line workers (mainly from global south, as usual…)
“Inequality and climate injustice is already the heart of the climate crisis.
“If people can’t be vaccinated and travel to be represented equally that’s undemocratic and would worsen the problem.
“Vaccine nationalism won’t solve the pandemic. Global problems need global solutions.”
She added: “If current trends continue and the COP26 has to be delayed that doesn’t mean we have to delay the urgent action required.
“We don’t have to wait for conferences nor anyone or anything else to dramatically start reducing our emissions.
“Solidarity and action can start today.”
More to follow…