The extraordinary plenary session was convened in a rare show of cross-partisan support, as all MPs bar the two minority deputies signed the request for it.
Opposition New Slovenia (NSi) deputy Matej Tonin said that the National Assembly wanted to find out why Slovenian banks needed to be bailed out and whether this operation was overpaid, adding that taxpayers need to get answers.
The process in which banks were recapitalised with a total of EUR 5bn at the end of 2013 while small junior bondholders were wiped out was explained to the MPs by Governor Boštjan Jazbec and Finance Ministry State Secretary Metod Dragonja.
Jazbec reiterated that the bank health check had been carried out by consultancies using established methods that apply in other EU countries.
"The review was conducted by independent consulting firms and Banka Slovenije did not affect the result. I cannot imagine what today's debate would have looked like if Banka Slovenije had indeed done that itself," he said.
Dragonja meanwhile said that the wiping out of small shareholders and holders of junior bonds was a necessary measure for the bailout to succeed. "The government has assessed that the measures were comprehensive, proportionate and successful."
Jazbec denied all allegations of impropriety, as well as the frequently voiced claim that the bailout was excessive. Banks are not overcapitalised, which is clear from indicators showing capital levels are still below the EU average, he said.
The governor also asserted all procedures and explanations had been released to the public. He admitted, however, that some of the decisions had not been immediately publicised for fear of triggering a run on the banks.
The MPs however wanted more information. Only if the methodology is revealed can doubts and suspicions about the bank health checks be lifted, Uroš Prikl, a deputy for the coalition Pensioners' Party (DeSUS) argued in the debate.
Several MPs argued that bank privatisation – all bailed out banks are slated to be partially or fully privatised – should be put on hold until all suspicions are cleared up.
"It is not too late yet to revoke certain measures," said Luka Mesec, the deputy group leader for the opposition United List (ZL).
The NKBM bank received EUR 1bn in state aid in a year and a half, and it is currently being sold for EUR 200m, he said, adding that the sale at such a low price should be reconsidered.
The calls for a halt of privatisation were not unequivocal, as the ruling Modern Centre Party (SMC) as well as the opposition New Slovenia (NSi) said it must continue.
"We have no intention of stopping privatisation, on the contrary, we want to accelerate it," said MP Jožef Horvat of the NSi, which gave the initiative for the plenary.
The opposition Alenka Bratušek Alliance (ZaAB) meanwhile advised caution in the privatisation procedure. Its leader Alenka Bratušek said that it should be checked whether the NKBM was over-capitalised and that the possible surplus should be returned to the budget.
Today's extraordinary session of parliament was just the latest in a series of parliamentary debates focused on the central bank's role in the bank bailout.
Pressure on the central bankers escalated after an apparent whistleblower alleged a series of irregularities in the methodology and overall procedures for assessing banks' health.
Most notably, it has been alleged that the central bank intentionally tweaked procedures to allow the bail-in of holders of junior bank debt, an allegation the central bank has vehemently denied.