A full hearing of the Green Party’s legal challenge against RTÉ’s criteria for inviting leaders to take part in its televised debate is due to begin today.

Eamon Ryan was not asked to participate because his party did not have at least three TDs in the outgoing Dáil.

This time round, its fielding candidates in every county, and Eamon Ryan feels he should be invited to take part in RTÉ’s leaders’ debate.

The Dublin Bay South candidate was not asked because of the party’s failure to meet the criteria set down by the broadcaster, which requires a party to have a minimum representation in the outgoing Dáil.

The Green Party failed to get anyone elected in 2011.

Permission to have a judicial review heard was granted last week and both sides appeared before the High Court a few days ago.

Counsel for the Greens said there was a degree of urgency because the debate is due to be broadcast next Monday.

It was given priority and is due to get underway this morning.