Turnbull gets asked on The Project if Kirribilli House is connected to the NBN. Courtesy Channel 10/The Project

THE National Broadband Network’s architect in charge of rolling out copper-based internet connections in Australia has resigned and will leave the company the day before the Federal Election.

NBN chief architect and telecommunications veteran Tony Cross will leave his role this Friday after spending four years designing the Multi-Technology Mix network introduced by Prime Minister Malcolm Turnbull that promised to deliver the NBN “sooner, cheaper and more affordably”.

However this copper-based network was recently slammed as a “colossal mistake” by the first NBN boss, Mike Quigley, who said it was in “shortsighted, expensive and backward-looking” and would ultimately cost billions of dollars to fix.

The copper-based network promised download speeds of just 25 megabits per second, compared to the 100mbps speed minimums delivered from fibre connections.

The reasons behind Mr Cross’ departure are not yet known but NBN Co issued a statement crediting the former Telstra and British Telecom executive with “a long list of achievements” during his six-year tenure.

“We expect to see him continue to make his mark in the industry and wish him well,” the statement said.

The timing of Mr Cross’ resignation comes at a critical time for the Coalition Government, however, following Mr Quigley’s scathing criticism of its slower Fibre-to-the-Node network.

Mr Turnbull also failed to mention the NBN during the Liberal Party’s campaign launch on Sunday despite its position as Australia’s largest infrastructure project.

The Coalition’s quiet approach comes as Labor promise to add as many as two million Fibre-to-the-Home connections to the network, if elected, though the party would not upgrade the pay-TV cable network or existing copper connections installed under the Turnbull Government’s policy.

An industry insider said it was not yet clear if Mr Cross’ departure signalled a new approach for the NBN Co, and a backflip for the Government, but engineers behind the project were critical of the current network.

“There’s more chance of finding rocking horse (poo) in the corridors of the NBN than finding an engineer who supports a multi-technology mix over copper,” the insider said.