[9] The environmental impact assessment study was completed in early 2010 and granted an approval permit by the Portuguese Environment Agency on 9 December 2010.

[12][13] However, shortly thereafter, forced by the 2010–2014 Portuguese financial crisis and the ensuing international bailout, the project was put on hold.

[14] In 2017, Ryanair was a major proponent of converting the Montijo Air Base into a facility for low-cost carriers; the company said that the new airport could be operational with as little as €25 million.

[6] In October 2019, the Portuguese Environment Agency gave approval for construction of Montijo Airport if it met certain conditions including sound insulation requirements and restrictions on flights between midnight and 6AM.

[16][17] In its 2024 decision, the Environment Agency cited increasing environmental concerns following new studies done in the area, most notably a negative opinion by the Institute for Nature Conservation and Forests.