The Department for Environment, Food and Rural Affairs (Defra) has lodged a fresh application with the High Court to postpone publication of its draft clean air plan until after the election.
The courts had given ministers until 16:00 on Monday 24 April to set out draft measures to combat illegal levels of nitrogen dioxide (NO2) pollution, after a 2016 court ruling said existing measures proposed by the government did not meet the requirements of law.
The general election is scheduled to take place on 8 June.
Defra argued the delay was necessary in order to comply with election ‘purdah’ rules limiting government announcements with political implications during the election period.
ClientEarth, has announced it is considering whether to challenge the application.
James Thornton, chief executive of the environment law organisation said: "The unacceptable last minute nature of the government's application late on Friday night, after the court had closed, has meant that we have spent the weekend considering our response.
"We are still examining our next steps. This is a question of public health and not of politics and for that reason we believe that the plans should be put in place without delay."
Thornton added: "Whichever party ends up in power after the June 8 will need this air quality plan to begin finally to tackle our illegal levels of pollution and prevent further illness and early deaths from poisonous toxins in the air we breathe."