Under the ruling, about 1 million casual workers who do regular shifts rostered in advance come could be entitled to annual leave, sick leave and other entitlements full-time employees get.

According to a Roy Morgan SMS survey of 881 Australian businesses, Queensland and its high proportion of workers in retail and tourism had the highest percentage of affected business  (45 per cent). The next most-affected was Western Australia (39 per cent), followed by NSW (33 per cent) and Victoria (28.5per cent).

Nationally, about a third of businesses said they would be affected and a quarter said the ruling would “deter them from hiring casual employees”. About 10 per cent of respondents said the ruling would have a large financial impact and 5.5 per cent said they would be forced to close.

Small and medium-sized businesses with fewer than 200 employees would suffer the biggest impact and industries such as transport, postal and warehousing would be most impacted (59 per cent). Wholesale (54 per cent) would also be hit, along with manufacturing (47 per cent), retail (45.5 per cent) and agriculture (40 per cent).

Hospitality and tourism were also likely to be heavily impacted but were not mentioned by the poll.

Roy Morgan chief executive Michele Levine said the business community and the union movement had to come together and reach a truly equitable and sensible outcome about how to handle the industrial relations implications of this decision in the interests of a healthy Australian jobs market.

“The biggest direct impact forecast by around a quarter of businesses is that they will be deterred from hiring casual employees in future. Many businesses mentioned ‘double-dipping’ and the fact that ‘casual workers already get a 20 per cent loading for sick pay and annual leave’.”

The 10.5 per cent of businesses who said the Federal Court’s ruling would have a “large financial impact” many mentioned the cost of back pay they would be forced to pay.