In an interview with Polish national radio, Polish Prime Minister Jaroslaw Kaczynski said Germany, with 82 million people, would have an unfair voting weight compared with Poland's 38 million people.
"If Poland had not had to live through the years of 1939-45, Poland would be today looking at the demographics of a country of 66 million," Kaczynski said. "We are only demanding one thing, that we get back what was taken from us."
The 27-member union's voting system says a majority is formed by 55 percent of member states making up 65 percent of the union's population, the Financial Times said.
Poland and the Czech Republic are proposing changes to the 55-65 percent voting formula to make it harder for big countries to control issues, the report said.