Australia's largest casino is facing a public dispute with thousands of its gaming and hospitality workers who have rejected management's wage offer and are demanding more pay for late-night and "graveyard" shifts on weekends.

Delegates for the 5500 workers at Crown Melbourne – Victoria's biggest single-site employer – last week knocked back a pay rise offer of 2.75 per cent, and are now preparing to "go public" with large-scale protests in the CBD.

Crown Melbourne staff work at least 40 weekends a year. Credit:Justin McManus

Crown staff are ramping up pressure for an increase of at least 5 per cent a year and new allowances of up to $3 an hour for all weekend work that falls between 7pm and 7am.

The industrial feud is the latest to erupt over the issue of weekend pay, and comes just weeks before the Fair Work Commission will deliver a much-anticipated ruling on whether to slash loadings across several industries nationally.