"We will only have socialist people around us like the French" if Brits were to vote to leave the European Union, the airline boss said in remarks at the London Aviation Club, Bloomberg reported.
Spohr believes that the economic impact of a Brexit on his company would be small – aviation has "historically been global and used to working over barriers. When it comes to our industry, being part of a common market is not as important," he said.
But he still hopes that "you guys [Britain] are staying in".
Lufthansa has spent years battling labour unions among pilots and flight attendants and likely hopes to ape the succesful example of British Airways rather than the ongoing acrimony at Air France, where a mob of workers assaulted bosses in October last year.
The German airline closed one front in its labour disputes by reaching a pay deal with ground staff in November, and agreed some bitterly-fought concessions over pay and pensions with aircrew in January.
But negotiations are continuing over other contentious points.
Brexit talks reaching crunch point
British Prime Minister David Cameron last week presented a draft deal with EU Council President Donald Tusk to MPs and voters at home.
It would include an "emergency brake" allowing Britain to reduce social benefits for EU migrants in the country as well as opt-outs for EU treaties' language committing member states to seek an "ever closer union".
Cameron is to speak at the traditional Matthiae-Mahl dinner in Hamburg Town Hall on Friday, which has welcomed around 400 guests from business, politics and diplomacy every year since 1356.
The British PM will be joint guest of honour with German Chancellor Angela Merkel – giving them a chance to put their heads together just a few days before a meeting of EU heads of state and government to discuss the British deal next week.
Merkel is keen to ensure that Britain "doesn't reach a decision that we think is wrong" in its referendum, as Finance Minister Wolfgang Schäuble delicately put it recently.