Fast rail linking Melbourne and Geelong won’t be delivered for decades if the state and federal governments go ahead with their expected airport rail link preference, a growing chorus of voices warn.

Concern for the future of the long-awaited fast rail is reaching fever pitch, amid reports the governments are set to announce the Melbourne Airport Rail Link (MARL) project will run trains through the new Metro Tunnel, rather than a new western tunnel.

Current and former mayors say a new tunnel between Melbourne and Sunshine is the only way to properly deliver fast rail to the state’s west.

Geelong Mayor Stephanie Asher and Wyndham Mayor Josh Gilligan have labelled a MARL without a new tunnel a “s--- deal”, while previous Geelong mayor Bruce Harwood has warned it would be a “disaster for Geelong” and push fast rail back decades and potentially generations.

“This tunnel is absolutely vital for creating future 35-minute Melbourne rail services to Geelong,” Cr Harwood said.

“In simple terms, only a new airport tunnel will untangle city from country trains.

“Abandoning the tunnel design will condemn regional Victoria to low economic growth and less opportunity.”

Committee for Geelong foundation chair Jim Cousins made a dire prediction for the future of fast rail to Geelong.

“We’ll all be dead before they actually decide to do something meaningful,” he said.

“There isn’t a bigger economic issue than fast rail and fixing overcrowding on Geelong’s rail line.”

The Rail Futures Institute (RFI) has claimed running the MARL through the metro tunnel, instead of a western tunnel, would limit the capacity to run more trains more often.

Cr Asher said a fast rail announcement was “imminent”, while the Geelong Advertiser understands it could be a matter of days before the state and federal governments announce that the MARL will run through the Metro Tunnel.

State Transport Minister Jacinta Allan yesterday would not confirm whether the Government had ruled out construction of a new tunnel between Sunshine and Melbourne for the MARL, nor say when a final decision was expected to be announced.

Instead, an unnamed government spokeswoman said, “We’re working closely with the Commonwealth Government on all options for airport rail — that will get people to and from the airport quickly with minimal interchanges.

“All options being assessed for the airport rail will stop at Sunshine for connections to Victoria’s major regional lines, such as Geelong, Ballarat and Bendigo.”

The latest concerns over Geelong’s fast rail project follow RFI claims a tunnel could allow for trains to run every 10 minutes on the Geelong line.

The state and federal governments signed an agreement in March last year to deliver the MARL, agreeing on a route taking the line from Melbourne Airport to Sunshine and the city, with the Sunshine alignment estimated to cost $8 billion-13 billion.

Both governments committed $5 billion each to the project.

The state and federal governments are currently working on details for the Western Rail Plan.