The future of the Waikato to Auckland passenger train service will be decided in a Transport Agency (NZTA) meeting on Thursday.
Te Huia is part way through a five-year trial but NZTA has not committed funding past the end of June.
Te Huia exceeded initial targets set for the service by the NZTA board, but not meeting new passenger targets, which were set by NZTA staff in 2022, according to an interim performance assessment prepared by Waikato Regional Council.
RNZ understands one option NZTA could consider is slashing the funding assistance rate (FAR) for Te Huia from 75.5 percent to 51 percent.
The council's draft 2024-2034 Long Term Plan said if funding in line with the FAR was not able to be secured long-term, the service would need to be reviewed, and it might not be able to continue.
"Council has signalled that with reduced support from NZTA, the service will be unaffordable for ratepayers."
The NZTA board will be reviewing the interim performance assessment. It was a condition set by the board that full funding of the five-year trial be released only after a two-year review.
No one from council has been invited to attend Thursday's meeting to address the report or answer questions from the NZTA board.
RNZ asked for details about the board meeting but was told NZTA board meetings are not public.
In comparison, Auckland Transport meeting are held publicly and agendas are published in advance.
Prime Minister Christopher Luxon previously called Te Huia a "white elephant" while Transport Minister Simeon Brown has incorrectly said the service was one of the most heavily subsidised public transport service in the country.
This led to concerns from Te Huia users that NZTA will not support funding the service for the remainder of the trial period.
A community-based petition to support the continuation of Hamilton to Auckland Te Huia train service has gained more than 4000 signatures in less than four days.
TRON local spokesperson Georgie Dansey said the government needed to commit to finishing the five-year trial so a fair assessment of the service could be made.
"It deserves a fair go," Dansey said.