Within 30 days of its conclusion or from the day that it becomes of public knowledge, the Portuguese Government has the right to trigger a screening procedure in the case of a legal transaction when:
- Direct or indirect control is acquired independently of the legal form; - In a direct or indirect way; - By natural or legal person or persons from countries outside the European Union or the European Economic Area; - Over strategic assets, defined as: the main infrastructures and assets assigned to defence and national security or to the supply of essential services in the areas of energy, transports, and communications; - If these may put into question, in a real and sufficiently serious manner, either: – National security and defence; – The country's supply of services deemed to be fundamental for the national interest. The investor has the possibility to request the Government to analyse the operation in order to obtain confirmation that a decision of opposition will not be taken.
"Article 1 – Object
This decree-law institutes the safeguard regime for strategic assets essential for ensuring defence and national security, and the Country's security of supply of services fundamental for the national interest, in the areas of energy, transports, and communications, as fundamental interests in public safety.
Article 2 – Definitions
For the purposes of this decree-law, the following definitions apply:
a) "Strategic assets", are the main infrastructures and assets assigned to defence and national security or to the supply of essential services in the areas of energy, transports, and communications.
b) "Control", is the possibility to exert a determining influence over the strategic asset, in accordance with article 36, paragraph 3, of Law 19/2012 of the 8th of May;
c) "Person of a country outside the European Union and the European Economic Area", is any natural or legal person whose domicile, statutory seat, or operational headquarters is not located either in a Member State of the European Union or of the European Economic Area.
Article 3 – Safeguard of strategic assets
1 – The Council of Ministers, following a proposal of the member of the Government responsible for the area where the strategic asset is integrated , may oppose, in accordance with article 4, operations from where it results, directly or indirectly, the acquisition of control, direct or indirect, by a person or persons of a country outside the European Union and of the European Economic Area, over strategic assets, independently of the respective legal form, should it be determined that these may put into question, in a real and sufficiently serious way, defence and national security, or the Country's security of supply of services fundamental for the national interest as defined by this decree-law.
2 – The real and sufficiently serious nature of the threat to defence and national security or to the Country's security of supply of services fundamental for the national interest referenced in paragraph 1 shall be based solely on the following criteria:
a) Physical security and integrity of the strategic assets;
b) The permanent availability and operability of the strategic assets, as well as their ability for promptly fulfilling obligations, in particular as regards public service obligations, which befall upon the people who control them, in accordance with the law;
c) The continuity, regularity, and quality of the services of general interest provided by the people who control the strategic assets;
d) The preservation of the confidentiality, imposed by law or public contract, of the data and information obtained in the exercise of their activity by the people controlling the strategic assets as well as the technologic resources needed for the management of the strategic assets; 
3 – Any operations from which results, directly or indirectly, the acquisition of direct or indirect control by a person or persons from countries outside the European Union are deemed susceptible to put into question the defence and national security or the security of the Country's supply of services fundamental for the national interest, in accordance with paragraph 1, if:
a) There is serious evidence, based in objective elements, of the existence of connections between the acquiring person and third countries which do not recognize or respect the fundamental principles of democracy and the rule of law, which represent a risk for the international community as a result of the nature of their alliances or which maintain relations with criminal or terrorist organizations, or with people linked with such organizations, taking into account existing official positions of the European Union on these matters;
b) The acquirer: 
i) Has, in the past, used the position of control held over other assets to create serious difficulties to the regular supply of essential public services in the country where these were located, or in neighbouring countries;
ii) Does not ensure the main assignment of the assets, as well as its reversal in accordance with the relevant concession contracts, if they exist, namely taking into account the inexistence of contractual provisions suitable for that effect;
c) The relevant operations result in the changing of the purpose of the strategic assets, should this threaten the permanent availability and operability of the assets for the prompt fulfilment of the applicable obligations, in particular public service obligations, in accordance with the law;
4 – The procedure of opposing the operations mentioned in paragraph 1 shall be taken in accordance with rules and obligations under the World Trade Organization or any other international agreement which bind the Portuguese Republic internationally.
Article 4 – Procedure for opposition
1 – Within 30 days counting from the conclusion of the transactions relating to an operation that results, directly or indirectly, in the acquisition of control, direct or indirect, by a person or persons from countries outside the European Union and the European Economic Area, over strategic assets, independently of the respective legal form, or counting from the date when such transactions become of public knowledge, should it occur afterwards, the member of the Government responsible the area in which the strategic asset is integrated may trigger an review procedure, by means of a duly justified decision, so as to review the risk of the operation for defence and national security or for the security of the Country's supply in services deemed fundamental for the national interest. [...]
5 – Within 60 days counting from the receipt of all the required information and documents to which paragraph 2 refers, the Council of Ministers, following the proposal of the member of the Government responsible for the area in which the strategic asset is integrated, may decide to oppose the operation, by means of a duly justified decision, in accordance with paragraph 1 and 2 of the previous article, and in accordance with applicable rules and legal principles, in particular the principle of proportionality.
6 – The absence of a decision within the deadline mentioned in the previous paragraph should be interpreted as a decision of non-opposition.
7 – Should a decision to oppose be adopted in accordance with paragraph 5, all acts and legal transactions referring to the operation in question are deemed to be null and void, including those concerning the economic operation or the exercise of rights over the assets or over their controlling entities. [...]" (Decree-Law 138/2014 (2014-09-15), Articles 1, 2, 3 and 4 [unofficial translation])
Decree-Law 138/2014 (2014-09-15), Articles 1, 2, 3 and 4
[<a href="https://data.dre.pt/eli/dec-lei/138/2014/09/15/p/dre/pt/html">Decree-Law</a>],[<a href="https://one.oecd.org/document/DAF/INV/RD(2019)7/en/pdf">Other</a>]