In a diplomatic note, Bratušek asks the Vatican whether it is aware of the actions of Slovenian Roman Catholic Church and whether it is acceptable for the Church to interfere in the independence of the judiciary.

Her letter comes days after the Slovenian Church's top dignitary expressed belief that the conviction against ex-PM Janez Janša will be overturned.

Commenting on the prison sentence handed to Democrats (SDS) leader Janša, Novo mesto Bishop Andrej Glavan said he was fully conceived by the dissenting opinions written by three of nine Constitutional Court judges in which they question the legality of the conviction.

The bishop, who is currently the Apostolic administrator of the Ljubljana Archdiocese, also said he felt that Slovenian "rule of law is in crisis and, maybe this is harsh, but the impression is that we are returning to the era of politically motivated show trials".

Moreover, the human rights commission of the Roman Catholic Church had in late July issued a letter in which it said that fears have grown in public that Slovenia was returning to the times of totalitarian regime and justice following Janša's conviction.

Responding to these comments, Bratušek asked the Holy See to take a stance on the actions of the Slovenian Church, the prime minister's party, the Alliance of Alenka Bratušek (ZaAB), said in a statement on Sunday.

Meanwhile, Bratušek commented on the letter during a visit to the city of Postojna on Sunday: "It is completely unacceptable and contrary to the Constitution that the Church interferes in the judiciary by passing comment on a concrete case."

Recounting a meeting with Pope Francis a year ago, Bratušek said that they had agreed "that corruption needs to be fought decisively - this is also what Pope Francis is striving for in the Church".

The outgoing prime minister stressed that "Pope Francis is taking measures in his institution very seriously and that even two Slovenian Church dignitaries had to leave their posts due to suspicions of business crimes".

This is in a reference to the resignations of the archbishops of Ljubljana and Maribor, Anton Stres and Marjan Turnšek,
in July 2013 in what was widely perceived as a move prompted by the Vatican over the financial collapse of the Maribor Archdiocese.

"I believe that the Vatican knows where the line should be drawn. As the prime minister, I'm bound to defend the Constitution and the rule of law," Bratušek added about her letter to the Vatican regarding the recent statements.