Weekday afternoons before the commuter rush kicks in aren't the busiest of times for radio listening, but the addition of Ray D'Arcy to the 3pm to 4.30pm slot on Radio 1 will spur a change in habits, predicts RTÉ radio commercial director Dan Healy.

"I suspect that Ray D'Arcy is going to create a Marian Finucane moment," he says.

"When Marian first moved from Liveline to the weekends, it was thought that weren't enough listeners available at those times, but she created that audience."

And while there has been an element of the grumpy old man about D’Arcy’s monologues on his new show, RTÉ bosses also forecast that he will bring in an ever-so-slightly younger audience.

"It's going to age down the demographic at Radio 1 without a doubt," says managing director of radio Jim Jennings.

Radio 1’s older listenership is disproportionately high – more than half of its listeners over the age of 55 and about a third have reached their 65th birthday.