Ryanair chief executive Michael O'Leary has compared RTÉ to a "rat-infested North Korean union shop" and said striking gardaí should be sacked in his speech to a Fine Gael fundraiser on Wednesday.

The businessman made the comments during an address to a pre-budget event organised by the south Dublin branch of Fine Gael which took place in the Shelbourne Hotel on Wednesday morning.

He gave his candid views on the national broadcaster, which he accused of peddling the views of hard-left union Trotskyites, while senior Government ministers including Michael Noonan, Leo Varadkar and Simon Coveney were sat down for a high-end breakfast, according to reports.

Introducing the Ryanair boss, Minister for Finance Noonan labelled him “Ireland’s leading altogether decent man”.

Mr O’Leary did not hold back with his views on threatened Garda strikes next month, calling the move “immoral”.

He said the situation should be handled like the US air traffic controller dispute in 1987, when mass sackings were ordered by then US president Ronald Reagan in a move that crippled the strikers.

He also criticised pension payments for gardaí who retire early, saying they do not contribute to the payments throughout their working lives.

The outspoken entrepreneur reserved some of his ire for a broad range of targets including cyclists and health and transport services which he said should be privatised.

He asked why the heads of bus and rail unions wanted to attend talks with Minister for Transport Shane Ross when they should have been concentrating on discussions with company management instead.

Mr O’Leary delivered the 40-minute oration to a behind-closed-doors, invite-only audience. The speech was said to have been well received by those present, who laughed and clapped at his stinging jibes.

He is expected to attend a similar event for Fianna Fáil next month.