Future Brisbane skyline revealed

Rival proponents vying for the right to develop a casino on prime riverfront land in Brisbane have laid their cards on the table.

The Queensland government's decision to move public service offices to a new site at 1 William Street will free up the existing government precinct between George Street and the Riverside Expressway after 2016.

Enter two giants - incumbent Brisbane casino owner Echo Entertainment and James Packer's Crown Resorts - who are battling it out for the once in a lifetime development opportunity.

The pair's rival consortiums on Monday revealed artist impressions of their proposals and both had exceeded the government's expectations, Deputy Premier Jeff Seeney said.

Both projects would include a casino, hotels, residential accommodation, a pedestrian bridge to South Bank and luxurious bars and restaurants.

Crown's proposal boasts a rooftop the size of The Gabba, public gardens, infinity pools and a suspended waterfall from its pedestrian bridge.

The Echo plan would feature a "signature addition" to the Brisbane skyline - an arc-shaped sky deck perched above a high-end hotel and ballroom.

Echo had the advantage of not needing an additional casino licence because it would relocate its existing Treasury Casino, chairman John O'Neill said.

The old site would be turned into a department store.

Both proponents on Monday responded to union accusations linking Hong Kong businessman Stanley Ho - who has been banned from a similar development in Sydney - to the Echo consortium.

"Let's be very clear - we are not in business with Stanley Ho," Echo's chief executive Matt Bekier said.

The company was providing 50 per cent of the capital, while a 25 per cent partner, Hong Kong's Chow Tai Fook, had a business relationship with Dr Ho.

The government will finalise the assessment process by mid-2015.