The National Broadband Network is giving up on plans to use Optus cables to deliver high-speed broadband.

Leaked NBN documents last year revealed the network managers were looking at a ‘Plan B’ for the Optus Hybrid Fibre Coaxial (HFC) network – which it had purchased for about $800 million – as it was deemed to be “not fully fit for purpose” with some equipment “arriving at the end of life”.

Less than a year after NBN called its ‘Plan B’ a “purely a theoretical exercise as part of our risk mitigation approach”, it now appears to be going ahead.

NBN says it will abandon the Optus HFC rollout in favour of a new technology; fibre-to-the-distribution-point (FTTdp).

That means up to 700,000 premises will now be hooked up with a technology colloquially known as fibre-to-the-driveway.

FTTdp falls halfway between Labor's fibre-to-most-homes approach and the Coalition's fibre-to-the-node alternative.

“This confirms what everyone already knew,” Labor communications spokesperson Michelle Rowland has told Fairfax.

“The HFC network was a lemon and could not deliver the broadband speeds and quality Australians expect and deserve.”