Ardern has highlighted the risk that New Zealanders could end up "stranded" in Australia, or having to do isolation upon their return.
Collins said that was a risk many would be able to accept.
"People need to make those decisions for themselves. It's not as though people are going to be stranded in a third world country."
Collins said the Government kept dangling the prospect of the bubble without delivering:
"We're aware there were 12 rounds of talks over nine months. Well, nine months is enough time to have a baby. It's time to get this one moving."
The Government initially said a bubble was expected by the end of March – but the chances of that are now almost nil.
There are still no firm signs of a two-way bubble, and on Monday Ardern conceded that it could make things more complicated if Australia went ahead with a proposal to open up its borders to more travellers from Singapore.
"What I would be interested in is how this would be seen by different states. If Australia makes the decision to open up and we think that poses risk to us then we will reconsider what our arrangements look like."
However, she insisted she had not given up on it.
"The last thing I would say is there has been a lot of speculation around whether it will happen at all. We have never stopped working on the issue of the transtasman bubble. Yes, we've had cases here and in Australia. Sometimes that's slowed things down, but the work has never stopped.
"We remain committed to it."
Ardern said it was more difficult to deal with state-by-state "bubbles" rather than the country-wide agreement with Australia she had initially wanted.
She said that made it harder to deal with issues such as arrangements with third countries, and quarantine for transit passengers.
Both Australia's Prime Minister Scott Morrison and NSW Premier Gladys Berejiklian have questioned why New Zealand was dragging its heels over opening its border to quarantine-free travel from Australia.
New Zealanders have been able to travel to Australia without quarantine since October. That was interrupted for a few days while New Zealand dealt with the outbreak in Auckland in February.
WHAT ABOUT THE COOK ISLANDS?
There are hopes a two-way bubble with the Cook Islands could become a reality soon after Ardern announced Cook Islands Prime Minister Mark Brown will visit New Zealand next week.
Brown will be the first country leader to visit New Zealand in more than a year, since Covid-19 border closures began.
The prospect of New Zealanders being able to come and go from the Cook Islands without quarantine is set to be top of the agenda – the Cook Islands expected to have all the elements required for the bubble in place by the end of the month and all that was required was for the New Zealand Government to agree to it.
Yesterday, Ardern would not say whether the Cooks bubble was likely to get the sign-off, but said the impact of the lack of tourism on the Cook Islands had been significant.
"So no doubt we will be talking about that together."
Ardern also expected to discuss the vaccine roll-out with Brown, saying the vaccine would provide an "extra buffer against risk".
New Zealand has offered to help provide vaccines to Pacific island countries, especially the two "realm countries" – the Cooks and Niue.
New Zealand allows people from the Cook Islands to come to New Zealand without going through quarantine, and has just added Niue to that list as well.
However, the Government is yet to give approval for New Zealanders (other than Cook Islands citizens and residents) to travel to the Cook Islands.
