"Personally and for Slovenia, I think portfolios that Slovenia used to have are very interesting, in particular environment ... as well as research," he said, noting that environmental policy was crucial for the entire planet while research is an area in which the EU has a lot of ambitions and major programmes such as Horizon 2020.

He also mentioned regional policy, digitalisation, international development cooperation and enlargement.

Regional policy is interesting because Slovenia is still a recipient of cohesion policy funds; in digitisation Slovenia has the ambition of becoming a global leader; and international development cooperation is interesting because the EU is the largest donor of development aid in the world.

The Slovenian government has previously mentioned enlargement as a portfolio of particular interest and its choice has been by some who criticised consider it a lightweight department, but Lenarčič disagrees with this assessment.

He acknowledged that enlargement was unlikely to happen during the term of the new commission, but he stressed that the department's purview was broader since the enlargement commissioner is in charge of managing relations with Turkey as well as the Western Balkans, which is Slovenia's neighbourhood.

Despite the history of relations with Croatia, it is not impossible that Slovenia get the enlargement portfolio since Croatia is no longer a candidate and Slovenia has excellent relations with all other countries.

"I don't think any department is bad. In every area you can do a lot of good for Europe and by extension for Slovenia," he said.

Overall, as one of the smaller member states and a country from Central and Eastern Europe, Slovenia deserves an appropriate portfolio, not least because the agreed package of appointments to top positions is geographically and demographically imbalanced, according to him.

While lauding and personally supporting Commission President elect Ursula von der Leyen's goal of gender parity on the Commission, he said it will be difficult to achieve since commissioners are nominated by member states.

He hopes she judges commissioner candidates by their expertise, not gender, noting that the Lisbon Treaty sets three criteria for commissioners - expertise, commitment to Europe and independence - all of which he satisfies.

"I'm convinced I satisfy these requirements and in that sense I don't see reasons for discrimination by any other personal circumstance," he said.

Lenarčič has not talked to van der Leyen yet and says he will gladly respond to her invitation for a meeting at any time.

Lenarčič sees promotion of shared European interests as the Commission's main task, noting that it needed to consider the political balance but had to always remain within the framework of the Lisbon Treaty.

"The outgoing Commission has not always followed this fundamental mission", he said, naming as examples the case of German motorway tolls and Schengen, when it repeatedly proposed extension of police checks on the internal borders with arguments that had little to do with facts on the ground.

"If I am confirmed member of the Commission, I'm going to insist on consistent compliance with the Commission's mission. We need a Commission that will protect EU law, respond to violations of the law, and promote the shared European interest," he stressed.

Asked whether van der Leyen brings a new approach, Lenarčič expects she will be committed to the shared mission and protection of law and sees no reason not to believe she will act accordingly.

As for van der Leyen's positions on issues such as migrations and the rule of law, Lenarčič said it was necessary to wait how she would chart her course.

Lenarčič is in favour of an "original solution" for a reform of the asylum system, arguing that it probably does not make much sense to insist on what has been on the table for four years.

Management of migrations will also determine the fate of Schengen and he said he would personally strive for a return to a fully functioning Schengen system.

Asked how he would treat Croatia in this context, Lenarčič said he will "act like a European Commissioner". The EU approach to this issue is very clear: when a member state fulfils all criteria to join the Schengen zone, it receives a recommendation from the Commission, whereupon the member states take the final decision.

Turning to the domestic political scene and criticism that he lacks democratic legitimacy, in particular from the Social Democrats (SD), Lenarčič said being elected is not one of the preconditions for becoming commissioner. In any case, he has been confirmed by a government that has democratic legitimacy.

He stressed he wanted unanimous endorsement in Slovenia, including from the SD, noting that support at home was important. Next week he will be quizzed by the parliamentary EU Affairs Committee and he hopes to meet all relevant stakeholders before the session.

"I'm hoping for openness and I hope I'm going to be allowed to convince them. This is all I want at this stage."