Italy warned the European Commission on Friday not to prevent Lufthansa's planned partial acquisition of state-owned Italian airline ITA, saying any obstacles to the deal would harm the nation.
Italian Transport Minister Matteo Salvini said a rejection from Brussels would be a "serious attack on Italy, to which we will not stand idly by."
Salvini, leader of the right-wing League of Italy party, said such a step could lead to the loss of thousands of jobs.
ITA was formed in 2020 after a restructuring of the failed Italian flag carrier Alitalia, which Rome acquired when various takeover bids failed.
After months of negotiations, Lufthansa agreed with the Italian government last May to take over a minority stake of 41%. In return, ITA is to receive €325 million ($352 million) in equity from Lufthansa.
Lufthansa could later acquire a further 49%, then the remaining 10%.
A final decision is to come in June, but so far, the European Commission has objected on competition grounds.
Salvini, who is also Italy's deputy prime minister, said: "If it is true that Brussels is waiting until the day after the European elections to deny the agreement between ITA and Lufthansa, that would be very serious."
Europeans are currently voting until Sunday in EU-wide elections. In Italy, the European Parliament polls are taking place on Saturday and Sunday.
Salvini's comments come after concessions were made by both Lufthansa and the Italian state to try to gain the regulator's approval.
The EU's top competition watchdog is concerned customers could face higher prices and lower quality airline services in and out of Italy due to restricted competition.
The commission first blocked Lufthansa's move to take a minority stake in ITA in January over similar competition issues and opened an investigation into the matter.
Short-haul airline routes between Italy and central European countries were highlighted in the commission's report with Lufthansa and ITA competing on direct and indirect flights.
Limited competition from Ryanair was the alternative for the region, the commission said. Reduced competition on long-haul routes between Italy, Japan, Canada and the United States was also noted. ITA's dominant position at Milan airport would also be reinforced.
Lufthansa already operates several hubs with the four airlines in its network: Lufthansa, Austrian, Swiss and Brussels Airlines.
