Repairs and maintenance staff at Darwin's multi-million-dollar export gas plant are threatening ongoing strike action, saying their pay and conditions are well below levels in other states.

Around 70 striking workers employed by Inpex contractor Trace Broadspectrum gathered outside the large-scale processing plant at Bladin Point on Wednesday morning.

Electrical Trade Union organiser David Hayes said the one-day action was being taken because enterprise bargaining agreement negotiations had hit a wall after 10 months of talks.

He said wages and conditions for the predominantly local maintenance workforce were below industry standard for such facilities and well below agreements in other states.

One protesting worker carried a sign reading: "This is a major hazardous facility, not a biscuit factory."

"Other plants the same as this in Gladstone for example or in WA, we see workers on those plants are paid up to 20 per cent more than workers here in Darwin."

A few hundred workers are now employed at the Inpex site, which was the biggest construction project in Northern Territory history and had an 8,000-strong, largely fly-in, fly-out workforce at the peak of construction.

Inpex said the maintenance contract would create around 160 local jobs when it was awarded to Trace Broadspectrum in 2017.

Ahead of a union meeting with the contractor scheduled for tomorrow, David Hayes said EBA negotiations were stuck on rates of pay as well as leave and rostered day off arrangements.

"The things that actually cost the company money are the sticking points that we are at at the moment," Mr Hayes said.

"We need to use the options that are available to us to put pressure on the company and get back to the table and make some decisions."

The union said staff expected the strike to interrupt some planned maintenance, although overall operations at the plant would not be affected.

Inpex and Trace Broadspectrum have been contacted for comment.