Alitalia pilots and flight attendants on Monday rejected contract terms offered by the new company which is aiming to launch a slimmed-down version of the troubled Italian carrier.
The rejection by two pilots unions and three flight attendants unions was unanimous.
Pilots association ANPAC said the offer was ''absolutely unacceptable''.
The head of another pilots union, Massimo Notari of Unione Piloti (UP), said the new terms would ''massacre'' the pilots.
The UP chief called for a ''deep reflection'' by Compagnia Aerea Italiana (CAI), the consortium set up to shape the viable parts of the old airline into a competitive airline.
Flight attendants union AVIA called the contract offer ''wrong and ideological'' and claimed it did not contain'' any consideration for the quality needs'' of Italy's premier airline.
''We had asked for more prudence because the seriousness of the situation has taken us onto thin ice,'' said Avia President Antonio Divietri.
Another flight-staff union, SDL, said it had been given ''insufficient'' details on the industrial plan and lay-offs.
The ANPAV flight attendant union called for ''radical changes'' to the plan.
National union federation UGL also came out against the plan.
Its transport pointman Roberto Pannella said ''breaking with the past can't mean mortifying the workers''.
He said CAI's industrial plan should take into account national contracts.
Pannella urged CAI to ''improve'' the plan.
The union rejection came less than an hour after CAI CEO Rocco Sabelli - No.2 to company chairman Roberto Colaninno - illustrated the plan.
After the rejection, Welfare Minister Maurizio Sacconi urged both sides to ''show patience and listen to each other''.
He said the government, which has shepherded the deal to keep Alitalia Italian, was ready to mediate.
Colannino has set up a 16-strong consortium to fund the relaunch, merge CAI with Italy's top private airline Air One and find a strategic foreign partner.
Air France-KLM has expressed interest in a minority stake if it sees a real prospect of profitability.
CAI has warned that the unions that they only have weeks to accept the terms or see the so-called Phoenix plan bite the dust.
The new Alitalia was launched ten days ago after the government changed Italy's bankruptcy laws to allow the airline's liabilities to be put into a 'bad company' which will be liquidated.