Act Party leader David Seymour says he is saddened to see "one of the world's great democracies in such chaos" after British Prime Minister Liz Truss' surprise resignation.
Truss, who quit after just 44 days in office, made a statement outside her 10 Downing St office, acknowledging she "cannot deliver the mandate on which I was elected by the Conservative Party".
Her resignation, which meant she becomes the shortest-serving Prime Minister in British history, has triggered another leadership contest. A new PM will be selected from within Conservative ranks by the end of next week.
Seymour said Truss' resignation should be a concern for the global community.
"This is a time when democratic countries need to set a good example to show our system works for people."
A growing number of British MPs had called for Truss to resign after weeks of turmoil sparked by her September 23 economic plan, which included a raft of tax cuts that spooked financial markets that investors worried Britain couldn't afford.
Seymour pushed back on the idea Truss' exit stemmed from tax cuts.
"I am also disheartened that Liz Truss' downfall is being widely misreported as being caused by tax cuts. It was not, it was caused by deficit spending, mostly caused by increased expenditure."
Boris Johnson - whose ouster as PM set off the disastrous chain of events leading to Truss' downfall - will chuck his hat in the ring to seize back the top job, the Times reports.
While hesitant to comment on another country's elections, Seymour did say Johnson oversaw improvements in New Zealanders' access to the UK and a free trade agreement with the UK for New Zealand.
A spokesperson for National leader Christopher Luxon said it was not appropriate to comment on the leadership of the UK Conservative Party.
However, the spokesperson did acknowledge "events" in the UK had reconfirmed the importance of "fiscal discipline and careful economic management".
"National will achieve tax reduction by stopping low-priority projects, removing bureaucratic waste and driving more value from Labour's massive explosion in Government spending," the spokesperson said.
A spokesperson for Prime Minister Jacinda Ardern said Truss' resignation was a matter for the UK, but said she looked forward to continuing New Zealand's "very strong relationship" with the UK.