Ms Collins announced a surprisingly wide reshuffle of party spokesperson roles on Saturday, which included Chris Bishop losing the shadow leadership of the House, ostensibly so he could concentrate on his primary role as Covid-19 response spokesman.
Mr Woodhouse, who has been deputy shadow leader for several years, now assumes the top role.
The job, managing party tactics and MPs in Parliament, involves a greater role in the top strategic levels of party planning.
While he has the right CV and level of parliamentary experience for the role, it also indicates a rehabilitation for Mr Woodhouse, who was chastised and demoted in July last year for not revealing to party leadership that he was privy to, but did not publicly release, confidential information about Covid-19 patients.
"I’m very excited about the opportunity, and I’ve probably come into the role with more base knowledge than most would," he said.
"It is a big job ensuring that the House runs smoothly, and behind the set piece in the debating chamber a huge amount of work goes on ... It is not quite as spontaneous as it might look."
Mr Woodhouse will have to work closely with Speaker Trevor Mallard, with whom he has had a running battle for several months over several aspects of House management.
"I have worked congenially with him already, notwithstanding some hostility which has brewed up over some issues ... When he does good on things we’ll say it; when he does bad on things we’ll say it," he said.
Mr Woodhouse surrenders the transport portfolio in taking up his new role.
He retains finance as his sole spokesman role, and it is expected that he will now be National’s pointman up against Deputy Prime Minister Grant Robertson.
"This gives me the opportunity to get much more involved with the finance stuff and I think that is going to be very important in the next month or so as Government spending and the debt that is incurred to allow that comes into sharper focus."
Simeon Brown will be Mr Woodhouse’s deputy.
Louise Upston takes on a new role as spokeswoman for regional economic development, and loses Land Information New Zealand to Christopher Luxon, who adds research, science and manufacturing to his existing roles.
Nicola Grigg and Simon O’Connor, respectively the acting spokespeople in the trade and export growth and internal affairs portfolios since Todd Muller announced he was stepping back from politics for personal reasons, now have those jobs permanently.
Harete Hipango, who re-entered Parliament upon the retirement of list MP Nick Smith, will be spokeswoman for children/Oranga Tamariki, Whanau Ora, Maori development and Maori tourism.
Parliament is due to resume sitting next week after a week-long hiatus due to the nationwide imposition of Alert Level 4.
Mr Woodhouse said he was still finalising details with Leader of the House Chris Hipkins on how Parliament would operate, but something similar to the restricted sitting hours in place during last year’s initial Covid-19 outbreak was likely.
He said as few National MPs as possible would travel to Wellington, but he, Ms Collins and chief whip Matt Doocey would relocate to the capital.