He said the "fight" was not so much with the NZTA as with the Crown, and on behalf of committee members and leaders he rejected an LTSA suggestion that they were putting speed and efficiency ahead of lives.
The committee released a statement requesting Waka Kotahi undertake a review of its decision.
"We believe that the decision was predetermined, and didn't not fully take into account the thousands of submissions against the proposal," a spokesperson said.
"We as leaders demand a fair share of crown investment. We need to be true to the whole of system approach, and need to look broader than safety and to the wider impacts on the community. We agree there are issues on our State Highway 5, but that these issues will not be solved solely through a reduction in speed.
"Auckland gets the holiday highways and a $16B light rail project, Wellington (nearly) gets Transmission Gully, Waikato has the bypass, Bay of Plenty has the Eastern Arterial, Manawatu gets a gorge replacement. We get nothing but a speed reduction.
"State Highway 5 is a lifeline for the region and our transport system. It is as important to us as the Auckland Harbour Bridge is to Auckland. It is vital to our competitiveness as a region, not least for the Port of Napier."
The limit is to come into effect on February 18, and signs are already in place, albeit with the new limit temporarily covered and reportedly already vandalised.
The Minister is due to see fellow Government MPs from Hawke's Bay to discuss the issue.
Napier MP Stuart Nash, Tukituki MP Anna Lorck and Meka Whaitiri (Ikaroa Rawhiti) say they've spoken to the Minister and he has agreed to "receive and discuss" the issues raised by the key stakeholders.
The Minister has however noted "it's not actually politicians who make these operational decisions".
"We will look to organise this meeting during our first week back in Parliament next week," the Hawke's Bay MPs said. "We will continue to work and meet with stakeholders regularly as agreed on Friday."