Labour has been accused of "hypocrisy" for signing New Zealand up to the world's largest free trade agreement because Labour MPs marched against a similar deal in 2016.
But Prime Minister Jacinda Ardern has defended signing up to the Regional Comprehensive Economic Partnership, or RCEP, because it will give New Zealand exporters a common set of rules with 14 other nations, she says.
RCEP is a trade agreement between 15 economies in the Asia-Pacific region that are home to almost a third of the world's population and take over half of New Zealand's exports.
New Zealand already has free trade deals with Australia, China, Malaysia, South Korea, Thailand and Singapore. But the new agreement will provide more access to Indonesia and give more clarity around trade rules within the region.
"I think one of the reasons there probably hasn't been as much discussion in New Zealand around this trade agreement is that it actually covers a number of countries where we already have some form of agreement," Ardern told The AM Show on Monday.
"The most important thing it does for New Zealand is it gives a combined rule book. At the moment our exporters are dealing with multiple different rules, multiple different ways of working across different countries, and so it creates a single rule book.
"It means, as well, for our primary producers where they're worried about perishable items being dealt with correctly because if they're not they lose their product, rules around them being cleared within a really tight timeframes."
National MP Chris Bishop, reacting on Twitter to news of the agreement, said it was hypocritical of Labour to support the deal when Labour MPs marched in 2016 against National's plan to sign the Trans-Pacific Partnership Agreement (TPP).
"Just a casual reminder that if [the National Party] had been signing this deal almost all Labour MPs would have organised marches against it and colluded with the far left to spread lies and misinformation about it," Bishop said.
Labour's concerns about the TPP centred on what's called a dispute resolution mechanism. It allows foreign investors to sue the Government over breaches of the trade agreement.
The TPP did not go ahead because President Donald Trump pulled out. The remaining 11 members negotiated the updated Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP), which the current Government signed up to.
New Zealand has side agreements with Australia, Brunei, Malaysia, Peru and Vietnam to ensure the investor dispute mechanism cannot be used against us.
Bishop said on Twitter it was "great" to see Labour "back in the mainstream", but he said the "hypocrisy is difficult to stomach".
National's trade spokesperson Todd Muller was more positive about the signing. He congratulated the Ministry of Foreign Affairs and Trade and hailed "bi-partisan steps forward".
Public submissions were sought on RCEP when negotiations first began in 2013. The RCEP agreement does not include an investor dispute settlement. But it will be reviewed in five years. No change can be made unless there is full agreement.
Ardern said the reason RCEP didn't get as much publicity because "it's really the rules that are helpful to us rather than removing tariffs".
She acknowledged that it would have been better for New Zealand if India had signed up. It pulled out last year, claiming its key concerns about agriculture and domestic industry were not being addressed.
"That would have been the big difference for us. If India were in, that would have been opening up an agreement with a country that we haven't managed to successfully negotiate a bilateral agreement," Ardern said.
"They withdrew quite late in the piece, so us being part of RCEP waiting for when they do re-join is important."
India has been given a fast-track process to re-join RCEP if it wants to.
New Zealand exported over $36 billion of goods to RCEP countries and nearly $12 billion of services in the year ending 2019. The RCEP agreement is expected to add $2 billion to New Zealand's economy.