Pat Kenny broke the news of his departure from The Late Late Show to his production team just one hour before the programme went to air last Friday night. And he named his possible successors as Ryan Tubridy, Miriam O'Callaghan, Gerry Ryan, Gráinne Seoige and Ray D'Arcy without passing comment on any individual.

There were emotional scenes at RTÉ both before the show and at the aftershow party where Kenny was joined by his wife, Cathy, producer Larry Masterson and other friends following his announcement on air.

Tubridy and O'Callaghan are the only two realistic candidates to replace Pat Kenny as host of show, according to informed sources in RTÉ.

Gerry Ryan has supporters within the station but there is a strong view that he "dirtied his bib" over his recent vocal opposition to taking a pay cut. Despite his eventual capitulation, it is believed his stock has diminished and he is out of the running for the prized prime time position.

Although there is a strong feeling in RTÉ that this is Pat Kenny's moment, supporters of both Tubridy and O'Callaghan were already starting to promote the qualities of their chosen candidate this weekend. Tubridy is regarded as the favourite to get the job.

One senior RTÉ source told the Sunday Tribune yesterday that a decision on Kenny's replacement would not be made for two months. However, he conceded Tubridy was in pole position in the race. Paddy Power bookmakers have already made Ryan Tubridy their 2/1 favourite to succeed Kenny.

Another RTÉ insider said: "Ryan has a unique talent which RTÉ spotted early on. You could say he's been groomed for The Late Late Show job for years with door after door opening for him.

"He worked on both Gerry Ryan's and Pat Kenny's radio shows. He was given his own slot on 2FM and then transported into a high-profile slot on RTÉ Radio 1.

"There's no doubt he's a talented broadcaster who has worked hard. I wouldn't be a bit surprised if the next door which opens for him in RTÉ is being host of The Late Late Show.

But taking on The Late Late Show will mean Tubridy (36) closing up shop on his chat show Tubridy Tonight, where he has built up a sizeable audience on Saturday nights and which also attracts considerable ad revenue.

"The last edition of Tubridy Tonight had 600,000 viewers," said one source close to Tubridy. "Ryan has his own brand. Why would he want to take over someone else's show? That said, getting offered The Late Late Show would be the most amazing opportunity for Ryan and he might not want to pass up."

Miriam O'Callaghan is another strong candidate for the Late Late job having straddled current affairs on Prime Time and the chat-show couch on Saturday Night with Miriam which she has hosted every summer since 2005.

However, some RTÉ insiders say the appointment of her husband Steve Carson as the station's director of programmes could hamper her chances.

"Six months ago Miriam could have walked into this," the source said. "Unfortunately her husband's new position is working against her. Steve Carson doesn't just work in RTÉ, he's part of station management, and there could potentially be a backlash if his wife was appointed the host of The Late Late Show.''

Kenny told his young daughters of his decision to leave the show before they left for school on Friday morning morning and said last night that he was looking forward to spending more time with his family.

One of his production team revealed: "It was after rehearsals at about 8pm, Pat pulled us all in and sat down with us. It was quite emotional but he did it with such dignity.

"People were so shocked as this was the first we had heard of it. He told us the news and said there were would be a lot of speculation as to who would get the job and he mentioned some names.

"'The usual suspects' he described them as, and they included Ryan Tubridy, Miriam O'Callaghan, Gerry Ryan, maybe Gráinne Seoige and Ray D'Arcy. He didn't pass any comment on these people, good or bad, other than mention their names.''

Kenny, who will continue with his daily morning radio show on Radio 1, will move into TV current affairs, long regarded as his area of strength. He will present a new-format show blending politics with satire, analysis and debate and scheduled to be broadcast on Monday nights, replacing Questions and Answers.

Previous Late Late host Gay Byrne yesterday refused to get drawn into any speculation about a new presenter for the show he hosted for 37 years. He told the Sunday Tribune: "I am not going to get into that whatsoever because no matter what I say about it, I offend a good number of people. If I recommend you, I offend 57 other people. If I recommend 57 other people, I offend you, so I'm not getting into it. There is nothing in that for me."

Talking about Pat Kenny's decision to leave the show, Byrne said: "The guy has come to the conclusion that at his age, does he want to spend the next 10 years doing The Late Late Show or does he want a bit more time to himself and it's a question which comes to us all, no matter whether you are a TV presenter or an accountant or a bank manager. I think he has taken a good decision. That's it.''