The union, which wants dialogue for the restructuring of the industry and a halting of layoffs, is ready to disrupt power supply if the government fails to respond. The government sees the move as unfounded.

The union has called on the government to cooperate with all stakeholders to form and adopt a decision on restructuring and financial reorganisation of the Slovenian energy sector, so that a safe and secure functioning of the system and supply are preserved.

It moreover demands that until such a document is adopted, all unilateral activity is stopped in relation to layoffs that are taking place under the guise of alleged rationalisation and optimisation.

The decision for the strike, which has also been endorsed by the country's largest union confederation, the ZSSS, was adopted last Friday, after being mulled for some time.

The union is afraid of foreign ownership in the sector, union representatives told the press in Ljubljana.

Unionist Valter Vodopivec said that the strike would be executed in line with the law and stepped up gradually, possibly to a point when disruptions in energy supply may be felt.

He explained that even in this event workers will be ready to intervene "in the case of an error, danger to property, lives".

Union president Branko Sevčnik stressed that problems would not be felt in hospitals, schools, kindergartens or other important institutions, adding jokingly that the government and parliament will be the first to lose electricity.

Vodopivec already said last week that "nobody in the country is seriously dealing" with what is one of the key segments of Slovenia's economy.

He said today that while the government is drafting energy guidelines for 2050, there will be nothing to decide on at that point if a strategy for "today and tomorrow" is not drawn up.

He added that the strike can be prevented or terminated early if government shows understanding for the demands and readiness to draw up the demanded document by an agreed deadline.

Sevčnikar said that all possibilities of dialogue have been exhausted. "The government failed to respond to any of the calls or threats, which is why we are here today."

He repeated the union has been trying to present its views to the government since 2010. It held a strike that year, stopping it following an agreement with the Economy Ministry, but has still been unable to make the country's leadership outline its vision for the sector.

Meanwhile, the government said that the demands issued do not justify the strike.

The union is raising issues which the government is aware of and which are being addressed in the widest possible dialogue with all stakeholders, the government Communication Office wrote.

It added that the demands pertaining to the management and restructuring of companies are not in the domain of the government but of the employer or the management and supervisors, which are appointed by the Slovenian Sovereign Holding.

The government moreover feels that all points of the agreement reached in 2014 by the union's strike committee and the Infrastructure Ministry are being honoured and executed.

Slovenia's biggest power producer, HSE, some of whose decisions have been criticised strongly by the Energy Sector Trade Union, also labelled the strike as unnecessary.

It defended its business decisions, saying it has "upgraded relations with banks in 2015...will publish after two years an annual report that will not include a qualified opinion by the auditor and has obtained a credit rating for the first time in the history of the HSE group".