Ahead of the vote on same-sex marriage on Friday, Finance Minister Michael Noonan has spoken of why he hopes the measure will pass.

"The worst thing of all in society is to be excluded...and gay people are being excluded for a long time," he said.

Mr Noonan says while Irish society has been moving to include people over the last generation, we still have one more step to go.

"It seems to me to be a logical step to make gay people fully included by allowing them to marry".

He said he cannot understand why people who will not lose anything themselves cannot agree to extend the right to others who want it.

"The overriding principle, as far as I'm concerned, is that all citizens of the country are equal under the law, they're equal under the Constitution, and then the Constitution should reflect that for gay people - as well as for everybody else".

In audio released exclusively to the independent radio network, Mr Noonan says a Yes vote will not affect "any of the rest of us", calling it 'another advance'.