A referendum in Romania aimed at blocking same-sex marriage failed to secure enough support this weekend, in what turned into something of a vote of confidence on the government.

Romanians were asked to vote on constitutional changes that would define marriage as a union between a man and a woman, making it impossible for gay couples to marry in the future.

The proposal had widespread support, including from the influential Orthodox Church and most major political parties.

A survey last week also found 90 percent of people favored the move.

But by the time polls closed at 1800GMT on Sunday, voter turnout was just 20.4 percent, below the 30 percent required for the result to be valid.

Gay couples are neither allowed to marry nor enter into a civil partnership in Romania.

But human rights groups had encouraged people to boycott the referendum, warning that a "Yes" result would restrict the rights of the LGBT community and minority groups.

Companies and popular musicians and artists joined in the boycott, and across the country, people were quoted saying they had better things to do, such as canning food and making wine.

"The aggressiveness of the 'Yes' campaign, the attempt to instill hatred against a minority, has made Romanians reticent to vote," sociologist Gelu Duminica told AFP news agency.

"Romanians rejected being divided and hating each other, it is a victory for Romanian democracy and moreover, Romanians rejected the involvement of the Orthodox Church in the state's secular affairs," added Vlad Viski of LGBT rights group MozaiQ, speaking to Reuters. 

The two-day referendum, which cost 40 million US dollars, also appeared to suffer from being backed by a ruling party under fire for weakening anti-corruption legislation.

Critics said the left-wing Social Democrats (PSD) used the vote to deflect attention from corruption scandals implicating some of their officials.

Party leader Liviu Dragnea is due in court on Monday to appeal a jail sentence for abuse of office.

"The PSD staked everything on the referendum, by associating with it and trying to capitalize on it," said Sergiu Miscoiu, a political science professor at Babes-Bolyai University.

"Many citizens have associated the initiative with the PSD and that is why they boycotted it... it is a major sanction against the government."

Final results from the referendum were expected on Monday.

(With input from wires)

(Top picture: A boy assists his mother while she casts her ballot in Ciorogarla, Romania, October 7, 2018. /VCG Photo)