Kresal, who already offered her resignation after an adverse opinion of the lease was issued by the Court of Audit on Tuesday, announced on Wednesday her irrevocable decision to stand down.

She also announced that she would seek a vote of confidence as the leader of the Liberal Democrats (LDS), the only remaining coalition partner to the Social Democrats (SD).

Prime Minister Borut Pahor, who declined to accept Kresal's resignation on Tuesday, said that today that he accepted and understood her decision.

Apart from finding a replacement for Kresal, Pahor still needs to nominate candidates to replace three ministers of the Zares party, which quit the ruling coalition in late June.

But his office said the PM maintained the main challenge now was passing the austerity budget for 2011, which was vital for the stability of public finance after the pension reform was rejected in the June referendum.

Head of the LDS council Anton Anderlic said the meeting taking a confidence vote on Kresal would be held in late August or early September, but he does not think the decision will affect its status.

Kresal's resignation does not mean a call for the party to leave the coalition, Anderlic said, adding that further developments mainly depended on the PM and whether an LDS candidate can fill the post.

Anderlic believes there are a few candidates in or close to the party that could replace Kresal, but said that no names had been discussed.

As "a sworn advocate of respect for the integrity and institutions of the rule of law" Kresal said she respected the Corruption Prevention Commission's opinion although she personally did not agree with it.

She reiterated her belief that the lease of the building for the NBI had been carried out lawfully and in good faith, adding that the whole of the Interior Ministry's team stood behind the procedure then.

Kresal's deputy at the time was Goran Klemencic, who resigned in May 2010 to become the head of the Corruption Prevention Commission, but he excluded himself from the procedure in which the commission looked into the controversial lease.

Kresal said that the commission had established that neither she nor her aides had asked for a gain in exchange for renting the building nor were they offered a benefit by the lessor or a third party.

The commission said that Kresal should have excluded herself from the procedure to find the premises for the NBI because she had been in private contacts with the lessor, but Kresal said that she did not lead the procedure.

She said that when assuming the office of interior minister she decided to make the fight against corruption and corporate crime the "absolute priority" of the police, which was the reason for forming the NBI.

It is for that reason that she decided to irrevocably resign from her post as of today at the moment the anti-graft body voiced doubt in her work and the work of her team, Kresal said.

The lease of the building from Ram Invest, owned by a person with personal ties to Kresal, was one of the reasons the opposition filed a motion to oust her in parliament in February, but the motion was voted down.

In the meantime, the Corruption Prevention Commission had received several tip-offs regarding the lease, which is why it initiated an inquiry. It was the commission that proposed to the Court of Audit to review the lease.

Political parties welcomed Kresal's resignation, some of them also calling for PM Pahor's resignation after he had failed to accept hers yesterday.

The Democrats (SDS), the biggest opposition party, said her resignation came too late, urging reaching agreement on a snap election as soon as possible.

Kresal, a 38-year-old lawyer, is standing down after nearly three years in office and after winning two confidence votes in parliament.

She won the first one in April 2009 when the SDS wanted to oust her for enabling retroactive restoring of permanent resident status to people who were deleted from permanent resident registry in 1992.

One year later the SDS and the other two opposition parties failed to oust Kresal over the lease of the building for the NBI and her alleged role in the return of bullmastiff dogs to a well-known Ljubljana doctor.

Kresal made her debut in politics as she was elected president of the LDS on 30 June 2007. She was elected MP in 2008 and became minister after her party entered the government.

Throughout her term, she faced accusations that she served interests of elites represented by her life companion, a well-known lawyer Miro Senica, who has been embroiled in several scandals.