(Bloomberg) -- Hungarian Prime Minister Viktor Orban is facing a surprise backlash against a new decree that gives free rein to cutting down the nation’s forests for firewood.

Almost 80,000 people and more than 300 organizations signed an online letter calling on Orban to withdraw the decree, which also threatens natural parks. Thousands attended a rally in Budapest on Friday, local media reported, in what was one of the the biggest protests since Orban’s re-election to a fifth term in April.

Orban approved the decree last week easing regulations on cutting native tree species and other restrictions to help Hungarians who are scrambling for alternative heating sources after Russia’s invasion of Ukraine drove energy costs higher.

His government was forced to scale back generous natural gas and electricity subsidies, leaving many people on the hook for exponentially rising utility bills.

“We understand that we need wood-based products and firewood, but this can’t go with the destruction of protected forests,” opponents of the plan said in the open letter, which was posted on the website of World Wildlife Hungary.

Opposition to the logging plan has gone beyond environmentalists and includes criticism from key officials from Orban’s own Fidesz party. 

The Fidesz mayor of Szekesfehervar, Hungary’s ninth-largest city by population, said on Tuesday that he would block logging in municipally owned forests and protected areas. In a post on Facebook, Andras Cser-Palkovics said the decree ran counter to Hungary’s climate strategy and the interests of future generations.

The government has since backtracked, saying the relaxed logging rules will only come into effect if the energy crisis reaches a level that leads to a shortage of firewood, spokeswoman Alexandra Szentkiralyi said on Thursday, triggering criticism that the caveat wasn’t included in the decree.

(Updates with protest in second paragraph.)

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