Updated at 4.30pm with FAA comment
The Planning Authority has given the go-ahead for the building of tunnels under the busy Sta Luċija roundabout.
The tunnels will link Triq tal-Barrani with Vjal Santa Luċija, easing traffic towards Triq Aldo Moro.
The project will be carried out in parallel with the Marsa junction flyovers.
Transport Minister Ian Borg said the tunnels would reduce travelling time in the area by 30 per cent while making the roads safer and cutting air pollution.
Flimkien għal Ambjent Aħjar warned that the roundabout would result in the destruction of an existing 1km stretch of mature trees and loss of agricultural land to widen traffic carriage-ways for private transit but would exclude adequate bicycle lanes and pedestrianised paths.
"Authorities are taking decisions with total disregard for the plans and policies aimed at supporting sustainable development that they themselves have put in place.
"Our institutions are failing us by simply encouraging further car-use and placing the burden of dealing with the inevitable build-up of road congestion on future generations," it wrote.