Radio New Zealand has confirmed changes to its Morning Report programme this afternoon.
As tipped, Simon Mercep will follow his co-host and step down from the show when Geoff Robinson leaves in April.
Mercep moves to a revamped afternoon show and current host Jim Mora joins Mary Wilson on a evening current format for Checkpoint.
Auckland-based Mercep is understood to have been unhappy about the delay in announcing new roles with much bigger changes being developed for other RNZ National shows.
Radio New Zealand is also working on a revamp of the Radio New Zealand news gathering processes, according to a well placed source.
Changes being planned are about both substance and style, a source said earlier, but changes to Morning Report are seen as the most urgent.
Mercep and Robinson had similar "softly, softly" styles.
RNZ says Morning Report with Geoff and Simon had rated well over the past three years - according to ratings compiled for RNZ by the market research firm Nielsen.
But the combination of Robinson and Mercep has been widely criticised.
Wilson has a reputation as "Scary Mary" with a hard-nosed interview style, and Mora might soften the programme.
Auckland-based Guyon Espiner replaces Robinson.
Radio New Zealand has decided that the show, managed out of Wellington studios, cannot not have two Auckland hosts, and that Espiner and Mercep were not the best combination.
Wellington journalist Susie Ferguson is expected to take over to work opposite Espiner.
Any changes to the Radio New Zealand news gathering process will draw intense scrutiny due to its role as New Zealand's only public broadcaster.
National Cabinet ministers have attacked the broadcaster as "Radio Labour" but news insiders say the problem is not bias but a reliance on party political reaction.
Radio New Zealand spokesman John Barr said that changes to Morning Report and another shows would be announced when reviews had been completed.
Head of news Don Rood - who has a key role at RNZ - said on January 24 that he had not held talks with Mercep about any new role.