MPs, ministers and mayors have received a tin of sardines in the mail to illustrate a rail network on the brink of bursting across the lower North Island.
The message that everything is not going swimmingly was sent by Greater Wellington Regional Council chairman Daran Ponter.
He wants the Government to inject the lion's share of $415m into new trains and rail upgrades, which would completely replace "vintage" units on longer distance services running from Wellington out to Masterton and Palmerston North.
"Lower North Island trains will be packed in like sardines come 2025 unless an urgent business case to Government for new hybrid trains gets the go ahead".
About 60 tins of sardines were paid for out of Ponter's own pocket to make the point. He took advantage of a sardine special at Pak'nSave Masterton with brands ranging from Pams to Brunswick.
Regional population growth has accelerated much faster than forecast over the last five years. It's increased by 35,000 against an initial forecast of 24,000, according to Census data.
The distribution of that growth is weighted in places like the Hutt Valley, Porirua and Kapiti Coast with people being pushed out of Wellington City due to an increasing lack of affordability.
GWRC reported an increase of 800,000 passengers this year bringing total patronage to 14.3 million.
Patronage growth on longer distance services from Wellington to Masterton and Palmerston North have already exceeded available capacity for both fleets.
"The increase in train users both within and beyond the metro network shows an urgent need to fund a modern fleet. With long procurement and manufacture lead times and ever-increasing demand, we must secure funding by 2020 if we hope to deliver by 2024", Ponter said.
The business case being proposed to the Government would replace both fleets to Masterton and Palmerston North with 15 four-car Dual Mode Multiple Units, which would run on electricity from overhead power wires, switching to alternative energy sources north of Waikanae and Upper Hutt.
The new units would also bolster Wellington based services to Kapiti Coast, the Hutt Valley and Johnsonville.
The proposal has come about with collaboration from, NZTA, KiwiRail, Transdev and Horizons Regional Council.
Ponter has been working to build support for the move by meeting with MPs based across the lower North Island.
He said he was confident there was cross party support following these discussions.
Most recently he met with Green Party MPs Gareth Hughes and Julie Anne Genter on Thursday.
Investment in more frequent, fast and reliable train services was a "no brainer", Genter said.
"These additional services could help take hundreds of cars off the roads coming into Wellington, meaning less congestion for those that do need to drive.
"This entire package is about half the cost of the oft-touted four lane motorway to Levin, so it's affordable."
National's Transport spokesperson Chris Bishop said they'd take a good look at the business case.
"There's no doubt the Wellington metro and wider network needs ongoing investment. Patronage is increasing and rail is an important part of Wellington's transport future."