Pro and anti-gay marriage campaigners from Ireland have got into a spat over funding – as the ‘no’ campaign is accused of receiving funding from US Christian groups.

The Republic of Ireland will on 22 May hold a referendum to decide whether to legalise same-sex marriage.

As the debate around same-sex marriage heats up, ‘yes’ campaigners have accused those in the ‘no’ camp of accepting funding from right wing US groups, despite foreign donations to lobby groups being illegal in Ireland.

The debate on Friday will be the first in the world where the electorate is asked to decide on the issue.

Recent polls have shown strong support for same-sex marriage, and earlier this week Irish Taoiseach Enda Kenny said he thought same-sex marriage will pass.

Those in the ‘yes’ campaign have said they are at a huge disadvantage, given the finances of the ‘no’ campaign which has booked TV and newspaper ads, spending tens of thousands of pounds over recent weeks.

The anti-equality campaign is reportedly funded in part by the National Organisation for Marriage (NOM), which has provided campaign support, urging followers to go to keepmarriage.org.

NOM denies funding the anti-marriage equality groups, however, noting that foreign donations to lobby groups are banned in Ireland.

The no campaign has also accused the yes camp of receiving funds from Irish-American multimillionaire Chuck Feeney.