UEFA has admitted its failure to deliver on a promise to plant 600,000 trees across the Euro 2020 host cities after being accused of "greenwashing".
Danish professor Ole John Nielsen made the accusation after it emerged that European football's governing body had not come close to achieving the promises they made before the coronavirus pandemic.
UEFA president Aleksander Ceferin said in September 2019 that the event, which was scheduled for the summer of 2020 but eventually took place 12 months later, would provide an "environmental legacy".
The aim was to plant 50,000 trees in each of the original 12 host cities, which included London, Glasgow and Dublin when initially announced.
But UEFA says the project was "ceased for reasons related to the pandemic".
It has been estimated that a tenth of the total trees promised were planted across Amsterdam and Baku, with no figures available from the other cities which hosted games in the tournament.
Nielsen told DR Sporten in Denmark: "Why should corona prevent people from going out and digging a hole in the ground to plant a tree?
"It was probably really one of the only things you could do during the pandemic, because it is an outdoor activity."
UEFA has said that it had switched to other projects and that a new sustainability strategy will be launched in December.