Barry Soper: National should unleash its rottweiler - Judith Collins

National has a pretty clear choice in just over a week's time - to flag the next election as a lost cause or to unleash a rottweiler who'd be capable of gnawing away at Labour's most valuable, and it would seem almost untouchable asset, Jacinda Ardern.

Simon Bridges and Amy Adams are capable former Cabinet Ministers but election winners they ain't.

If either of them get the nod to lead the party tomorrow week, the strongest single party in Opposition in the country's history will have kissed goodbye to any success in 2020 and will have simply opened the way for someone yet to be considered to step up to the plate, and in a caucus that size there'll be plenty itching to have a crack. After the expected resignations that'll follow, whoever is eventually elected leader might still not be in Parliament yet.

Unleash Judith Collins and even though the chances of the Government changing, short of the unlikely event of it falling apart, it at least won't be as cocksure as it was when it was sworn in last October.

Since becoming the first to announce her candidacy just under a week ago, Collins has shown her mettle, accusing Ardern of spending too much time talking about herself and not enough on the meaty issues. Even the sacrosanct Mother of the Nation mantle was stripped away with Collins declaring pregnancy and the Prime Ministership ain't no thing - she ran a law firm when she was pregnant.

Collins' acerbic style is quintessentially the opposite to the earnest persona of not just Bridges and Adams but of Ardern herself, and that's what sets her apart. She's also a slick social media operator, announcing her candidacy on Twitter and far outstripping the popularity of the other two with 12,500 followers. Although in fairness on the more sedate Facebook, Adams has more likes that the other two put together.

But it's public opinion that counts, out in the real world, and on that score Collins is winning hands down with opinion poll soundings, even if they are relatively unscientific.

When it comes to the vote count in caucus, anything can happen if one of the candidates isn't a clear winner on the first ballot, which is highly unlikely. If there are three in the race, the lowest polling candidate will drop off and the votes they attract will swing to the other two.

The 10 new MPs in their caucus are now experiencing lobbying like they've probably never experienced before and as the week progresses that'll just intensify.

Like Jacinda Ardern last October, they've been given a responsibility that they weren't expecting.