Auckland Transport is considering building central city rail tunnels with just one underground station to start with - to the fury of council transport leader Mike Lee.
The Auckland Council transport organisation says a staged approach to developing stations along a 3.5km route for the twin tunnels from Britomart to Mt Eden is among options it is considering for "optimising" project management and finances.
One scenario would be to open the tunnel with just a station near Aotea Square in the first instance, to be followed by others below Pitt St and Symonds St as finances and patronage dictate for a project which threatens to balloon to almost $3 billion.
It is even unclear whether the tunnels would form a true central city loop, as land constraints mean it may initially have only a western connection with the existing network where it will emerge at Mt Eden, rather than an east-facing link as well.
But Mr Lee, chairman of the council's transport committee and an Auckland Transport board member, said opening the tunnels with just one station would be similar to building the harbour bridge with just four traffic lanes.
Soon after that happened in 1959 - forcing the end of many ferry services - the bridge reached capacity, raising an urgent need for the four clip-on lanes to be added 10 years later.
"I find their reasoning impossible to understand," he said of Auckland Transport officials considering the staged railway approach.
"A City Rail Link with one station is like a harbour bridge with four lanes or Britomart with two lines - we should learn from the false economies of the past."
Mr Lee accused the transport organisation of "talking the costs up, inaccurately".
An official cost figure of $2.86 billion, as well as being in inflation-adjusted dollars to 2021, includes $336 million for new trains and $140 million for what Auckland Transport is calling "other network optimisation".
The organisation has denied the accuracy of a figure of $2.94 billion reported to councillors by chief executive David Warburton at a closed workshop a fortnight ago and seized on by critics of the project such as the Automobile Association.
An official acknowledged the $2.86 billion estimate included separating the western railway line from intersecting roads, and was therefore not part of the core project.
Auckland Transport also hopes to make a construction cost saving of $166 million, which Mr Lee said was because its estimates were out of kilter with international prices.
"There's no political support for Auckland Transport to be short-changing the City Rail Link," he said.
"What we want from Auckland Transport is accurate reporting of the costs in here and now figures that everyone knows and understands."
The Auckland Transport official said the organisation was looking at a range of ideas, after cost concerns raised by ratepayers and others.