Supporters of a No vote in the referendum on same-sex marriage have raised concerns about the foreign funding of groups supporting the Yes side.
Senator Ronan Mullen has said it is wrong that billionaire philanthropist Chuck Feeney is funding many of the Yes groups - while also providing support for government agency Túsla.
Senator Mullen says funding for a state agency is always welcome - but not if it influences a public referendum debate.
“Is there a problem with an Irish government agency getting money from an international organisation? No," Mr Mullen said.
“Is there a problem with campaigns around massive social change in Ireland getting millions of euro over a number of years - and some of these organisations which are campaigning are actually charities – is that a problem with that that the public should be concerned with? Yes," he added.
The Child and Family Support Agency is chaired by a Yes supporter, and has also cut its funding for the Catholic marriage agency Accord.
Mr Mullen’s Seanad colleague David Norris has said he has no concerns about Chuck Feeney's funding of groups on the Yes side, and that Mr Feeney funds a number of groups as one of the biggest donor’s to organisations in Ireland. Mr Norris said he believes there is no issue with the money.
“He’s given huge amounts of money to Trinity, to UCD, to the development of law centres, to programmes for the jobless,” Mr Norris said.
“He is a most wonderful man and yes he supports Amnesty (International), but Amnesty does a whole lot of other things as well.
Mr Norris added: “All these red herrings, I wish we could get them out of the way.”