Bulgaria's president said Wednesday that his party might support reviving a major joint nuclear power project with Russia abandoned earlier this year even if a January referendum fails as expected to attract enough voters to be valid.

"If more than 20 percent of the voters take part in the referendum and half of them say 'yes', parliament will have to review the issue within three months," Rosen Plevneliev said.

"The parliamentary ban on Belene will then fall," said the president, who comes from the ruling right-wing GERB party of Prime Minister Boyko Borisov, which has a near-majority in parliament.

The government in March scrapped a deal with a Russian firm to build a second nuclear plant at Belene, citing financial constraints, angering Moscow which is suing Sofia for one billion euros ($1.3 billion) in compensation.

The opposition Socialists pressed for a revival of the deal and forced the January 27 referendum by collecting more than 540,000 signatures.

In order to be valid, it has to attract a voter turnout equal or higher than that at the last general elections, or 4.35 million people -- 70 percent of Bulgaria's 6.2 million voters -- which Plevneliev said was unlikely.

Bulgarians are generally pro-nuclear, with 62.5 percent of the respondents in a recent poll of the state NCIOM institute backing its development, while 37.5 percent voted against.