Unions have approval to strike throughout the entirety of the Brisbane Festival and beyond, with more shutdowns on the table indefinitely if negotiations do not progress.

The Australian Maritime Officers Union and Maritime Union of Australia had a request approved to extend their protected action ballot for 30 days on August 26, which was not contested by ferry operator RiverCity Ferries.

That includes options for shutdowns which are yet to be deployed, but as the union has already exercised its right to hold unlimited consecutive stoppages of an hour, it can shut ferries again at any time provided three clear days’ notice is given.

AMOU industrial officer Tracey Ellis explained the union can take action “forever” until an agreement is reached with RiverCity Ferries.

“We can do it past September,” she said.

“There is still plenty of time for them to come back to us to resolve this. We would welcome discussion.”

The group chief executive of Kelsian Group Limited, the owner of RiverCity Ferries, had a pay increase of $500,000 in the last financial year.

The parties have not yet spoken since the Riverfire ferry action was announced on Tuesday.

Queensland Police have not changed their operational plans despite the ferry shut down and are confident they have enough contingency plans in place to move people through the city safely even if more transport nodes are taken out of action.

Riverfire Operations Commander and North Brisbane District Acting Chief Superintendent Simon Tayler said they were “exceptionally comfortable” with the planning work completed in the eight months leading in.

About 450,000 people are expected to watch Riverfire in Brisbane and more than 27,000 passengers took ferry trips to and from the fireworks extravaganza last year.

“We’re not seeing it as a major risk to us or to our plans,” he said.

“It’s not insignificant (but) it’s certainly not like we were talking about taking out the rail network or the buses.”

As an example of a contingency, if Central Station had to be shut in an emergency police would quickly activate to shut streets down and move passengers on foot to Roma St, Mr Tayler said.

He advised visitors to follow social media pages for QPS for real-time information on streets being shut, and TransLink.

Artemus Group chief executive Luke Fraser — the owners of Howard Smith Wharves — said they look forward to celebrating with thousands of visitors in the riverside precinct, noting how important the ferry services typically are.

“The Brisbane River and the CityCat play a key role in how people move throughout our city, particularly during major events like Riverfire,” he said.

“We have seen first-hand how locals and visitors have embraced our CityCats and rely on them to enjoy the city safely and easily.”

Ma Pa Me restaurant co-owner Andrew Jefferies — based in South Bank — said he supports CityCat operators wanting better working conditions but noted it comes at a cost to Brisbane locals on the precinct’s biggest night of the year.

“They are holding negotiations for ransom,” he said.

Brisbane Festival was contacted for comment.