Alexander Temerko, the director of U.K. energy company Aquind, who has donated nearly £700,000 to the Conservatives since 2012, said that Hunt apparently “doesn’t know what the Soviet Union was.”

Speaking to POLITICO at the Tory conference, Ukrainian-born Temerko acknowledged that Hunt was comparing the “attitudes” of the two blocs, not the ideologies, but nevertheless delivered a stern critique of the foreign secretary’s words, which have also angered Eastern European EU member countries.

“I think it’s wrong. The Soviet Union was an ideological state … planned economy, through security, control of all scales of life. I think Jeremy doesn’t know what the Soviet Union was. His comparison is very incorrect,” Temerko said.

“The European Union has such different principles. I lived in the Soviet Union. I was born in Ukraine when it was part of the Soviet Union.”

“The Soviet Union was the worst form of state, an anti-humanist state. Europe is different: free trade, free movement.”