Juncker's spokesman Margaritis Schinas, who announced the meeting for 6 PM, said Juncker will check three main criteria with Bulc like he did with all other candidates: competence, independence and commitment to Europe.

Juncker, who has not yet commented on the 50-year-old minister for development but is said to be happy that Slovenia put forward a female candidate, will decide after the interview if she is fit to become a candidate and for which portfolio.

If he okays Bulc, he will draw up a new list of all commissioner candidates that will need to be confirmed by member states, probably within a day or two. After that, a hearing of Bulc is to follow in the European Parliament.

It is not yet clear which department Bulc will get and there has been speculation that the IT expert and innovator could be offered the post of commissioner for the digital economy and society in place of Germany's Günther Oettinger.

Oettinger as the current energy commissioner would in turn get the energy union post initially reserved for Slovenia's first candidate, ex-PM Alenka Bratušek, who was rejected by the European Parliament last week. However, other scenarios are also said to be possible.