Despite the funds being cut to support public transport, Mr Bennett believes that it should not be a matter of either/or.
"We need to be working on that rail option, but the thing is the extension is the opportunity that is in front of us now. We have done all that work getting the expressway up to that point and it would be silly to stop that now."
Mr Bennett says the higher fuel tax that Labour is proposing will be enough to fund both.
A fuel tax increase of between 9 and 12 cents a litre has been proposed while Aucklanders will face fuel tax hikes of about 20 cents a litre if the Government's increases and a regional fuel tax are brought in.
He would also like to see the full rail link upgraded from the start which includes electrification of the tracks from Pokeno north. Currently the plan is to get a diesel train running from Hamilton to Papakura which Mr Bennett labelled as the cheap option.
Labour list MP Jamie Strange has said that no decision had been made yet over the the expressway extension.
"There is only a slight drop, but there is still money available," Mr Strange said. "It has gone from something like $4.1 billion to $3.8 billion so it has only gone down a little bit, but over the next three years there is still some money available."
Mr Strange also said the final decision will be up to NZTA and this has caused confusion.
"They are autonomous, and what will happen is the council in our region will put together a regional transport proposal."
Mr Strange said it his expectation that the Cambridge to Piarere extension and the Southern Links will both be included in that transport proposal.
"NZTA also has both of those on their list. The first priority for them is finishing the Waikato Expressway and that will be done in 2020. The second priority is Southern Links and the third is Cambridge to Piarere."
The consultation process for the Policy Statement on Transport closes on May 2.