Rome - Alitalia's Italian government-appointed commissioner on Saturday told labour union representatives that dwindling fuel supplies at the near-bankrupt airline meant that it could not guarantee flights beyond another day, news reports said.

"For tomorrow we have our flights guaranteed, but not for Monday. They are no longer supplying us with fuel," Commissioner Augusto Fantozzi told the unions, according to the ANSA news agency.

He also warned that Alitalia would begin to lay-off flight crews from 34 planes which have already been grounded as part of cost-cutting measures, ANSA said.

Fantozzi summoned union representatives for afternoon talks a day after the collapse of their negotiations with a group of private Italian investors, CAI, seeking to take over the state-controlled airline.

Earlier Saturday, Prime Minister Silvio Berlusconi lashed out at the unions saying their opposition to the government-approved CAI bid is politically motivated.

Unions reject the estimated 7,000 job cuts CAI says are necessary to save Alitalia.

"This situation worries me very much. I can't understand what is happening and why this suicidal attitude (by the unions) exists," Berlusconi was quoted as saying by ANSA.

"There are political motivations that have nothing to do with the needs of the workers," the premier added.

Berlusconi, who was returning to Rome after attending a trade fair in the southern city of Bari, said he intended to intervene "personally" in an effort to save Alitalia from bankruptcy, without providing further details.

Berlusconi campaigned prior to his April election triumph for Alitalia to remain in Italian hands and has championed CAI's bid as an alternative to one made earlier this year by French-Dutch airline Air France-KLM.

Air France-KLM withdrew its bid, which was supported by Italy's previous centre-left government, when it became clear that Berlusconi, once in office, would have opposed it.

It is estimated that Alitalia loses around 2 million euros (2.7 million dollars) a day. (dpa)