All 11 Croatian members of the European Parliament called on the European Commission on Monday to confirm Croatia's preparedness to join the Schengen Area and resist the "politicisation of the accession process" by Slovenian MEPs.

The Commission should resist “the politicisation attempt,” it must remain politically unbiased and, based on objective benchmarks, adopt a decision that Croatia is technically prepared to join the Schengen Area, they say in a joint letter.

The letter, they add, comes in the wake of a letter by six of Slovenia’s nine MEPs to the Commission in which they expressed doubts about Croatia’s capacity to join Schengen.

Last Friday, the Slovenian MEPs sent a letter to the presidents of the incumbent and the next Commission, Jean-Claude Juncker and Ursula von der Leyen, the presidents of the incumbent and the next European Council, Donald Tusk and Charles Michel, and Slovenian Prime Minister Marjan Sarec.

In the letter, they say it is questionable whether Croatia meets the technical requirements for Schengen and that a decision on giving the green light should not be made by the Juncker Commission, which put it on its agenda just before the end of its term, but by the next Commission.

In their response, the Croatian MEPs say that Croatia meets all the technical requirements and that they expect the Commission to give the green light on Tuesday.

They warn that a potential delay due to political pressure and unsubstantiated doubts about Croatia’s technical and legal preparedness would undermine the Commission’s credibility as well as the trust of EU citizens.

“The Schengen Area is one of the most important achievements of the EU. The free flow of people, goods and capital within Schengen will ensure better transport connections, stronger external borders and simpler economic cooperation between Croatia and the rest of the EU,” Croatian MEPs said, adding that Croatia’s entry is in the interest of Croatia, Slovenia as well as all of the EU.

They reminded the Commission that since 2016 Croatia has met all the technical requirements and that this has been confirmed by the Commission’s Directorate-General for Migration and Home Affairs. They added that since 2015 the Juncker Commission has been actively following Croatia’s technical preparedness to join Schengen and that this gives it absolute legitimacy to make the final decision.

In their letter, the Slovenian MEPs say that a decision that Croatia meets the technical requirements would have long term and strategic consequences for Europe, and that they find it incomprehensible and difficult to accept that the decision should be made by the outgoing Commission.

Slovenian PM Sarec and Foreign Minister Miro Cerar have objected a number of times to the Juncker Commission deciding whether Croatia meets the Schengen requirements. A previous Slovenian government headed by Cerar considered Juncker biased towards Croatia when the Commission was deciding on whether to join a Slovenian suit against Croatia at the European Court of Justice.