"AHP was pleased to receive the news of the decision to issue the Environmental Impact Statement (DIA) for Montijo airport,” Martins said in a written reply sent to Lusa. “This decision is very important for the growth of tourism in Portugal.”

On 21 January, the Portuguese Environment Agency (APA) issued a favourable if conditional opinion on the planned new airport at Montijo, on the south bank of the River Tagus.

"With the construction of this airport, we will achieve an increase in airport capacity in the country of about 30%, in addition to allowing Lisbon airport to improve its conditions of service to tourists, placing it in the ranking of major airports worldwide,” Martins said. “This is good news for Portugal, but especially for Lisbon, which has exhausted its airport capacity and where the supply continues to increase."

The plans call for Lisbon's existing Humberto Delgado Airport to be expanded as well as the building of a new facility.

Also on 21 January, in a statement, the APA said that it had issued an impact statement "concerning the complementary airport of Montijo, confirming the favourable decision conditioned on the adoption of Solution 2 of the prior report of the southern extension of Runway 01/19 and alternative solution of the prior study of the road link to the A12" motorway.

This decision requires the airports authority, ANA - Aeroportos de Portugal, to comply with around 160 minimisation and compensation measures costing around €48 million, the note said.

APA added that the measures - related to birds, noise, mobility and climate change - provide for minimising and offsetting the negative environmental impacts of the project, and are to be detailed in the execution phase of the project.

On 22 January, ANA also took a positive view on the Montijo airport impact assessment but stressed that the APA had not accepted its alternative proposals.

"ANA notes as positive the issuing of the DIA which definitively makes the implementation of the Lisbon airport project possible and stabilises the dual solution composed of Lisbon airport and Montijo airport, under the terms defined by the Government," the company said in a written statement sent to Lusa. "This confirms ANA's commitment to move forward with the investment in Montijo."

Under the impact statement issued on Tuesday, the Montijo airport project is to be undertaken in two phases: the opening phase (scheduled to start in 2022 with conclusion projected for 2032) and the expansion phase (scheduled for 2054 through 2062).