Greenpeace says it will take legal action to force the Dutch government to end financial support to the airline KLM.
In June, the Netherlands announced it would provide €3.4 billion in aid to the Dutch airline to "face the crisis" of the COVID-19 pandemic.
But in a press release, the NGO said the aid is not accompanied by sufficient climate conditions.
"The cabinet is failing to make firm agreements with KLM on pollution control," said Dewi Zloch, a climate expert at Greenpeace.
"This state aid plunges us deeper into the climate crisis, which is contrary to the duty of care that the Dutch government has for its citizens."
Greenpeace says it will pursue the legal case if the Dutch government does not respond with changes by October 1.
The aid package from the Netherlands includes €2.4 billion in bank grants and a direct state loan to KLM.
The bailout terms include new environmental and noise pollution targets for KLM which were insisted upon by the Dutch parliament, as well as cost cuts.
However, Greenpeace said the environmental conditions do not go far enough.
"More sustainable aviation will not be achieved with the slow measures that are currently in place," Zloch denounced, calling for an end to flights of fewer than one thousand kilometres.
Last year, the Dutch High Court ordered the country's government to reduce greenhouse gas emissions by at least 25% below 1990 levels, in line with climate goals.
The environmental group, Urgenda, who brought the case to court hailed the decision as "historic" and "groundbreaking".
Euronews asked the Dutch government and KLM to respond but they had not done so by the time of publication.