"Now Aucklanders, for a third time since the 2017 general election, have to face another round of fare increases," national coordinator Jon Reeves said in a statement.

The PTUA says both Labour and the Greens campaigned on being pro-public transport however they "have not delivered".

"The PTUA would like the Government to urgently provide AT with the additional $3.5 million shortfall to stop the fare increase, or better still provide AT with funds to enable significant fare reductions for all public transport users," Reeves said.

"If the Government took climate change, the environment and congestion seriously they would have increased funding. The Government allowed Auckland Council to quickly increase local petrol taxes, but how about something for public transport users?"

AT has defended the rise, saying it's keeping more than half the fares at the current price

"Operating costs increasing through inflationary pressures on, for example, diesel, and the introduction of many new bus services, unfortunately can't be completely absorbed, so we have had to introduce some slight fare increases," says Mark Lambert, the executive general manager of integrated networks.

"The fare changes do not cover the full cost of inflation with the balance covered by service efficiencies and AT's own cost reductions, and funding increases from Auckland Council and the NZ Transport Agency."

Transport Minister Phil Twyford told Newshub it's up to Auckland Transport to manage its fares.

"Our Government wants to ease congestion and give Aucklanders real transport choices, which is why we have increased the amount we are spending on public transport infrastructure in Auckland through NZTA by nearly fivefold compared to the last Government," he said.

"We have also increased our Government's contribution to public transport services in Auckland by around $200m, which is projected to help grow patronage by 15 percent - that's over 100m trips every year.

"It's up to Auckland Transport to manage their fares and I note that they are also introducing free one-zone bus and train trips that connect with ferry travel and free weekend travel for under-16s."