Newshub understands the battle to be Prime Minister is over, with a senior MP saying Bill English has 45 votes, a landslide majority.

The successful candidate only needs the support of 30 members from National's 60-member caucus to win the leadership.

So now the real scrap is for Deputy.

Paula Bennett - "the Westie" - has pulled the handbrake on going for the top job, instead chucking her lot in for Deputy in National's leadership burnout.

Simon Bridges wants the job as well. Both are backing the expected winner, Mr English, and both are touting the complementary qualities they offer to his safe pair of hands.

"He's a Southland farmer and I'm a city girl and I think we'd make a good combo," says Ms Bennett.

Mr Bridges says: "Bill English offers strength and stability - what I offer is the change and rejuvenation."

Then there's star performer Amy Adams, who isn't ruling out joining the deputy race.

National is divided between Mr Key's senior team, which wants a cosy handover, and the backbench, which wants generational change.

Ms Bennett is part of Mr Key's inner sanctum dubbed the "Kitchen Cabinet," while Mr Bridges is seeking support from the back bench.