John Campbell and Hilary Barry: Could this be the new face of Seven Sharp?

Viewers were left stunned by Mike Hosking and Toni Street's surprise news last night that tonight's episode of Seven Sharp will be their last.

The announcement follows months of industry rumour and speculation about changes to TVNZ's prime time line up, including ongoing reports that Hilary Barry will move on from Breakfast.

TVNZ has strenuously denied such claims, with news boss John Gillespie labeling a Herald report "blatant lies".

"When they talk about Hilary going to primetime, that's a lie plain and simple," he told Fairfax in July.

Last month, the Press Council dismissed a complaint by TVNZ against the Herald for continuing to report the speculation, saying: "The history of journalism is replete with stories being shown to be true despite a history of categorical denials."

The Herald understands Barry has now signed a contract for the 7pm timeslot.

But who will join her behind the desk remains a mystery. Insiders say that while Street's decision to leave was widely known, Hosking's move to join her was a last minute development, throwing the network into a state of flux.

With Barry moving to prime time, there will be more musical chairs on Breakfast, where it's believed Jack Tame will remain put.

Last month, Breakfast lost another presenter when Brodie Kane quit the network to host The Hits breakfast radio show in Christchurch.

So who are the frontrunners and where might they land?

JOHN CAMPBELL

In the words of John Lennon, imagine... Hilary was brought to tears when John Campbell left TV3 in 2015. The pair are old friends and have proven on-screen chemistry. Campbell isn't afraid to ask the tough questions and would bring a harder news edge to TVNZ's line up. It would also see the pair reunited with their former 3 News colleague Alistair Wilkison, who took over as executive producer this year. Would Campbell quit National Radio for TVNZ? Would the TVNZ audience embrace Campbell's social activism and liberal leanings? Watch this space.

MELISSA STOKES

Newsreader Melissa Stokes is a regular fill-in on Breakfast and one of the few survivors from last year's major overhaul, which saw Rawdon Christie, Nadine Chalmers-Ross and Peter Williams all dropped from the programme. A former Europe correspondent, Stokes has serious news chops but also has a proven ability to laugh at herself - as last year's Media Ocre Awards regularly highlighted. Having filled in on every TVNZ show going, it's about time the bosses gave her a show of her own.

CAROLYN ROBINSON

A popular newsreader at TV3, Carolyn Robinson - or Caro - made the jump to TVNZ in 2016, joining Seven Sharp as a reporter. It wasn't long before they had her presenting 20/20 on TVNZ2 and she has been a regular fill-in for Toni Street. Rumour is she was keen to take over permanently but with Hilary heading to prime time, Caro might find she needs to set her alarm a little earlier next year.

DANIEL FAITAUA

Warm, funny and good pals with Hilary, Daniel Faitaua could find himself joining his Breakfast co-host at the opposite end of the day. Faitaua's life experience as a father of three is a good fit with the Seven Sharp audience, although insiders say he and Barry together risk being "too nice".

MELISSA DAVIES

A few months ago, a rumour reached the Spy team, suggesting that Newshub presenter Melissa Davies was lining up to join Jack Tame at TVNZ. At the time, it didn't make a lot of sense - but perhaps our spies were better placed than we gave them credit for? Could Davies be heading for Breakfast? 

SAM WALLACE

Media commentators have been quick to pick Sam Wallace as a replacement for Hosking but we're not so sure. Wallace is well liked and a natural on-screen but he has his hands full working alongside Street and Sarah Gandy on The Hits breakfast show and we don't think he'll be signing up for another full-time role.

ALI PUGH

A long-time favourite with Breakfast viewers, former reporter and presenter Ali Pugh stepped down two years ago when she welcomed her daughter Thea to the world. Moving back to her hometown Christchurch, Pugh announced last year she was "much happier" having left Breakfast. But there's no doubting her star appeal will have her high on the replacement list.

MATT CHISHOLM

Resident larrikin Matt Chisholm is a favourite with TVNZ bosses, fronting its flagship reality series Survivor NZ this year. Already part of the Seven Sharp team, Chisholm is familiar to the audience and has the same provincial charm that made Street so popular with viewers.