Climate action group ACAN has called on architects at Foster + Partners and Zaha Hadid Architects to take "meaningful action outside of your employment" amid an escalating row over airport projects.
The body condemned the two studios for refusing to stop designing airports and urged staff to take action over an issue that is dividing the profession.
"If you work for Foster + Partners, ZHA or indeed any practice, please know that you are welcome to join our movement and take meaningful action outside of your employment," said Architects Climate Action Network (ACAN) in a statement on its website.
"It is vital we speak truth to power and take action together."
Feud over airport projects escalates 
ACAN's statement, posted yesterday, comes amid an increasingly acrimonious row over whether working on new airport projects is compatible with decarbonisation goals. It came after the two London architects resigned from Architects Declare, another climate action group, following criticisms of the practices' ongoing work in the aviation sector.
Architecture writer Christine Murray, editor of The Developer, asked why ACAN and Architects Declare were picking a fight over aviation, which accounts for around three per cent of global carbon emissions.
Meanwhile, new construction and existing buildings are responsible for around 40 per cent of atmospheric carbon, Murray pointed out on Twitter.
Squabble has "divided the profession into good guys and bad g...