The UK’s biggest teaching union is to decide whether to object to fossil fuel giant Ineos sponsoring the school Daily Mile initiative over allegations the company is using the event to greenwash its image.

Campaigners accuse Ineos, owned by the UK’s richest man, Sir Jim Ratcliffe, of endangering the wellbeing of future generations through its fracking activities and plastics production.

On Saturday the executive of the National Education Union will debate a call for the schools to oppose Ineos’s sponsorship of the event, which sees tens of thousands of children take part in an outdoor run each week.

The campaign is being supported by the UK Student Climate Network, which helped coordinate the recent school strikes that saw more than a million young people take part in demonstrations over the escalating global warming crisis.

Anna Taylor, 18, co-founder of the group, said: “Climate criminals like Ineos, with their fracking for plastics agenda, are already destroying our environment and fuelling climate change for profit.

“Allowing them unfettered access to classrooms and attempting to normalise their fossil fuels ‘extractivism’ with our generation is totally and utterly unacceptable and must be outlawed.”

The Daily Mile is promoted as “a social physical activity, with children running or jogging – at their own pace – in the fresh air with friends”. But campaigners say its promotion of “fresh air and a healthy lifestyle” is at odds with the reality of Ineos’s operations.

Two primary schools in Strensall and Copmanthorpe, York – both of which are within areas licensed for fracking – have withdrawn form the Daily Mile after the link was highlighted by local campaigners.

Adrian Palmer, a parent from the Copmanthorpe school, said: “Our schools are unwittingly falling foul of these Ineos PR stunts as they don’t have time to research and make the connection between the Daily Mile and its controversial petrochemical fracking company backers … Having this Ineos PR in our schools is akin to a tobacco company sponsoring the school’s sports day.”

An Ineos spokesperson said: “Ineos has supported the Daily Mile for many years and has seen this project grow from modest beginnings to a global success. We are proud of the role we have played in this growth and we intend to go on supporting the charity, which helps improve children’s health and wellbeing across the world.”