The well-known entrepreneur is suing the national broadcaster over the infamous Frontline tweetgate affair which is credited with derailing his campaign.
Mr Gallagher has engaged top lawyer Paul Tweed to take legal action, which may result in a substantial compensation payout. It is understood that Mr Gallagher is particularly annoyed by comments made by Frontline presenter, Pat Kenny, in which he told him to "get over" the incident.
The remarks -- described as "provocative" by Mr Tweed -- will also form part of the court action. Station bosses have just over a week to decide whether they will fight it.
Mr Tweed, who has represented celebrities such as Louis Walsh and Britney Spears, today formally lodged the proceedings with the High Court.
In a statement, he said that Mr Gallagher feels he has "no alternative" but to sue RTE.
"My client believes that he has been left with no alternative but to seek the assistance of the Court, given RTE's persistent refusal to offer any adequate or appropriate redress for what was the totally unacceptable conduct by them of the Frontline broadcast, and which has had dramatic and extremely serious consequences for my client."
The former Dragon's Den star will ask that the High Court declares that the programme was neither objective, fair or impartial.
Mr Gallagher is also believed to be seeking damages for alleged breach of statutory duty, alleged negligence and breach of duty and alleged misfeasance in public offence.
RTE bosses were today consulting their own legal team in order to decide whether to contest the court action.