About 1000 Crown staff and their supporters marched on the Melbourne casino on Tuesday, the United Workers Union says.

Workers are fighting for better pay and job security and are in the final stages of a ballot on whether to strike for the first time in 16 years during the upcoming Spring Racing Carnival.

"Staff believe as one of the largest and most profitable employers in Australia, Crown should be able to offer a full time job to anyone who wants one," union national secretary Tim Kennedy said.

A Crown spokesman said an agreement was expected to be finalised soon and the casino prided itself on employment and training opportunities.

"Like many other employers in the hospitality industry, we provide a flexible workplace which caters to thousands of staff who prefer to work on a part-time or casual basis as it gives them the flexibility to pursue other work, study or family opportunities," he said.

"Where staff would like to work additional hours, depending on their availability and trading conditions, we strive to provide them with the opportunity to increase their hours worked."

But the pay fight is not the only issue engulfing Crown.

Both the Victorian and Australian governments are facing questions about scrutiny of the company's Melbourne precinct amid renewed allegations of money laundering and other illegal activity.

Crown denies the allegations.

The federal government on Tuesday shot down an attempt by independent Tasmanian MP Andrew Wilkie to establish a royal commission into Crown.

Attorney-General Christian Porter labelled the idea "completely premature", given the multiple investigations currently underway.

Mr Wilkie has been a vocal critic of Crown and on Tuesday released security footage from the casino showing what he believes could be money laundering.

Victorian Greens MP Ellen Sandell also pushed for a royal commission.

But state Gaming Minister Marlene Kairouz echoed Mr Porter on the number of investigations already underway.

She said it was unclear what was going on in footage of stacks of money being exchanged for gaming chips and had asked the Victorian regulator to work with national agency Austrac to determine any illegality.

"But it's not uncommon for high roller rooms to have large amounts of cash in those rooms and let me remind the member that cash is indeed a legal tender," Ms Kairouz said.

Australian Associated Press