Air France KLM is in talks with trades unions over its 138m offer to take over Alitalia.
The bid has already been accepted by Italy's caretaker government but will also need the backing of the new government due to be formed after the general election on April 13-14.
The AF KLM bid offers one share for every 160 in the near bankrupt Italian national carrier.
But it is conditional on approval from the unions and on a 300m bridging loan from the Italian government to stave off imminent bankruptcy.
Talks with the unions began last Tuesday and AF KLM said they are due to be concluded on Monday, March 31.
The unions have opposed the take-over because it will mean cuts in jobs among the 19,000 workforce.
There would also be cuts in flights, mainly at Malpensa Airport which serves Milan.
Fabrizio Solani, an official of the CGIL union, was quoted in La Repubblica as describing the take-over as "unconditioinal surrender."
One of the pilots' unions Anpac also said it would be fighting the bid.
Some politicians, many from Northern League, a separatist party, also oppose the take-over.
Silvio Berlusconi, leader of the opposition and currently ahead in the opinion polls for the election, has said he would prefer an Italian solution but has not said he would reject the AF KLM offer.
But Tommaso Padoa-Schioppa, the caretaker finance minister, has accepted the offer for the 49.9% held by the government and has told Alitalia also to accept the bid.