Eden-Monaro candidate Kristy McBain said the study would be funded if Labor was elected at the next federal election. She also promised to lobby the current government for the funding.

The Narooma Bridge is a notorious bottleneck, where larger vehicles cross double lines at the northern end. Australian Community Media approached Eden-Monaro candidates for comment regarding Labor's call.

Ms McBain said community engagement would be essential so "regardless of what happens in this byelection or after, the wishes of the local community are put first rather than petty politics".

"Whether that's a realigned bridge or a bypass - it's something that feasibility study will shape out," she said.

Aside from safety, Ms McBain said improvements to the Princes Highway would "unlock the potential" of the South Coast.

"At the moment we don't have b-double access, and that stops businesses from growing and it also stops new businesses from coming to the area."

She wants the government's investments to be "targeted" to certain parts of the highway which will "assist communities to grow and prosper".

"With the bushfire cleanup, we are seeing more trucks on the highway than ever," she said.

"This is an area that needs to be prioritised now, given the black summer we have just been through.

"Any infrastructure investment that is going to unlock the potential for our economies to grow, should be moved forward."

However, Liberal candidate Fiona Kotvojs said a study on the bridge was already completed.

"The NSW Government has undertaken the study into the requirements of the Princes Highway - it's there and they are working on that," Dr Kotvojs said.

"The important thing is to invest money where it makes a difference, not to duplicate investments.

"The importance of transport in this area is nothing new to me. It is something I supported strongly last year.

"I am committed to planning for a long term replacement for Brown Mountain, and the upgrades of the Princes Highway - in particular the four bridges (Narooma, Brogo, Allsop's and Double Creek) and other points where there are serious safety concerns.

New Liberals candidate Karen Porter said the NSW Government should do more.

"I would lobby the State Government and put pressure on them to prioritise the Narooma Bridge and upgrading of the Princes Highway," Ms Porter said.

Science Party candidate James Jansson agreed that "upgrades provide an opportunity to stimulate the economy while investing long-term in the community".

"I support improvements in roads led by the state government; In particular, I consider black spot improvement to be the highest priority," he said.

Sustainable Australia candidate Joy Angel supported Labor's call. Ms Angel said a study must consider the potential for a Narooma bypass.

"The approach to the Narooma bridge from the north is very problematic, being quite steep downhill with very tight curves and poor visibility," she said.

"Semi-trailers and trucks with trailers require skilled handling, along with holidaymakers towing large caravans. The bridge itself is narrow, so that large trucks, trailers, caravans and motor homes experience serious risk when passing in opposite directions.

"Due to the required raising of the bridge to let large boats in and out, it causes traffic jams day and is a serious risk during the fire season if the bridge was to be stuck or damaged and unable to operate after being opened.

"Like Batemans Bay, the Narooma Bridge needs to be upgraded, but should be considered within a holistic approach to what is happening with the Princes Highway in general, including any long-term plans to bypass the town.

"It is essential that the $5 million feasibility study includes the potential for a Narooma bypass which would be a boon for through traffic on the highway and allow Narooma to regain its coastal village appeal without the constant flow of large trucks and through-traffic."

Ms McBain said the federal government had made "no action" and she wanted the Princes Highway recognised as an area for priority federal funding, "especially after what we have just been through".

"It's something that should be brought forward and prioritised, as part of the recovery in areas like this, on the back of COVID and bushfires," Ms McBain said.