"It's amazing how many people get 'sick' the day before a long weekend but it's an obvious stunt that only serves to damage personal reputations and morale in the workplace," Mr Cartwright said in a statement. "Nobody is fooled by the Friday 'sickie'." Instead, Mr Cartwright urges employees to talk to their boss about extra leave.

The Victorian Employers' Chamber of Commerce and Industry could not predict how many workers might take a sickie on Friday.

But its chief executive, Mark Stone, said employers regularly reported such concerns near public holidays, and many had introduced annual holidays planning to try to minimise the issue of unexpected leave.

He said bosses or business owners should ensure their staff were aware of annual and personal leave policies, such as whether evidence of illness was required. They should also be clear about how employees should notify the company when they were genuinely ill, for example by telephone or email.

Meanwhile, Peter Strong, the executive director of the Council of Small Business of Australia, said small business employees considering pulling a heart muscle on Friday should think about how they would be affecting their workmates, not to mention the owner.