Ljubljana - Defence Minister Matej Tonin has announced that Environment Minister Andrej Vizjak can no longer count on the support of his party New Slovenia (NSi) following the statements he made in a leaked conversation with a spa company boss 14 years ago.

Appearing on late night new shows on the commercial POP TV station and the public broadcaster TV Slovenija on Wednesday, the NSi leader suggested it would be best if Vizjak resigned himself.

Tonin said the party had had "in-depth discussion" with Minister Vizjak and Prime Minister Janez Janša about the matter. After what they heard "Vizjak can no longer count on the support of the NSi".

In both interviews Tonin said the scandal involving Vizjak from the time that he served as economy minister disrupted the government's work and put it in an awkward position.

He indicated there was a possibility that Vizjak, a member of Janša's Democratic Party (SDS), stepped down himself or "take decisions that would alleviate the burden on everyone".

Then there is the prime minister who decides on ministerial appointments and resignations and the last instance is the opposition-sponsored motion of no confidence in Vizjak where Tonin said Vizjak would not have the NSi's support.

POP TV has over the past two weeks aired several sections of a lengthy recording of Vizjak's conversation in 2007 with Bojan Petan, the CEO of the spa company Terme Čatež and the publishing group DZS.

On the tape Vizjak is heard offering Petan agreement on the management of Terme Čatež, the biggest owners of which at the time were the companies affiliated with Petan and the state, as well as a deal on the withdrawal of the spa company's own shares.

Vizjak is also heard offering Petan the state's support in his takeover of another spa company, Terme Olimia, while warning him over action to challenge the decisions of the Terme Čatež shareholders' meeting, asserting the government would find a judge "to break his nuts".

While Vizjak acknowledged last week that the recording was authentic, he said his goal at the time was to protect the interests of the state in the takeover of Terme Čatež.

Despite suggestions that he was not ruling out his resignation, Vizjak today insisted on his intention to "deny all the allegations against him in a detailed and argument-based response to the motion of no confidence".

The newspaper Delo has reported that Foreign Minister Anže Logar, the head of the SDS council, has written to Janša that Vizjak should step aside, which Janša denied on his Twitter profile today.

"I'm reading speculation about a letter about Minister Andrej Vizjak's resignation that Minister Anže Logar is supposed to have sent," Janša tweeted, adding that he had not received any letter with such content from Logar or any other SDS member.

The STA has approached Janša about whether Vizjak still enjoys his trust but has not yet received an answer.

Danijel Krivec, the head of the SDS deputy group, said yesterday the party would decide on whether the minister still enjoyed their trust after he sets out his case prior to the vote of no confidence.

For the vote of no confidence to succeed it would have to be backed by 46 of the 90 members of the National Assembly.