A row broke out between the 'No' campaign and RTÉ just hours ahead of the final televised referendum debate, Independent.ie can reveal.

The broadcaster was this evening trying to find somebody to debate Health Minister Simon Harris after solicitor Cora Sherlock withdrew from ‘Prime Time’ which is due to air at 9.35pm.

It is understood the 'No' side wanted to substitute Ms Sherlock with the Iona Institute’s Maria Steen, who was widely seen as the star performer during last week’s ‘Claire Byrne Live’ debate.

Sources described the situation as a 'Mexican stand-off' with just hours to air.

The 'No' camp insisted there is no falling out between the various groups, including Love Both and Savethe8th.

Barrister Ben O Floinn told Independent.ie: "I can confirm that the joint nominee of all 'No' group is Maria Steen for tonight’s programme.

We'll be bringing the @loveboth8 podium to our press events for the rest of the campaign to remind @SimonHarrisTD that now he has accepted our challenge, he only has to name the time and the place for a debate with us. #LoveBothVoteNo #8thref pic.twitter.com/GdompLNRyK — Cora Sherlock (@CoraSherlock) May 3, 2018

"I have been asked by all the groups to press for her inclusion. RTÉ Prime Time are resisting this."

The broadcaster said the programme, hosted by Miriam O’Callaghan and David McCullough, will go ahead.

However, a spokesperson said she was not in a position to comment any further "at this time".

The programme began this evening with Health Minister Simon Harris speaking for the 'Yes' side standing opposite Sinn Féin TD Peadar Toíbín who is anti-repeal of the Eighth Amendment.

At the beginning of the programme, presenter Miriam O'Callaghan acknowledged the absence of any female debaters.

"We were to be joined by two women," Ms O'Callaghan said.

"But unfortunately Cora Sherlock pulled out and, for reasons of balance, we had to reduce to two people."

RTÉ’s objection to Ms Steen is based on her participation in a similar debate last week. It is understood the broadcaster has also taken issue with the idea that either side of the debate would dictate their line-up.

However, 'No' campaigners are arguing that Dr Peter Boylan was allowed to take part in both debates on the Late Late Show and Claire Byrne Live.

Online Editors