ACTU secretary Sally McManus says good bosses should be allowing their employees to work from home amid soaring COVID-19 infections.
It follows Chief Medical Officer Paul Kelly saying businesses should be looking at flexible arrangements for their workers in a bid to stem rising case numbers.
Ms McManus said due to a lack of health orders, allowing people to work from home came down to an employer choosing to accept the recommendation.
"Every good employer at the moment, until this wave recedes, should be allowing their workers to work from home as they have done at various other times over the last few years," she told ABC radio on Friday.
When asked about unions trying to enshrine flexible arrangements for workers into enterprise agreements, Ms McManus said face-to-face contact was still important for some workplaces.
"I don't think it's good to have a one-size fits all (approach) ... there should be options for it," she said.
"Lots of big employers with unions negotiated ... say three days off, two days on, so those are the type of models being negotiated and I think they're really successful.
"Where it can be done, why shouldn't it be? A lot of employers realise that happier workers means a more productive workforce."
The Financial Sector Union has called for the right to negotiate work-from-home arrangements to be formalised in upcoming enterprise agreements with major banks.
Opposition Leader Peter Dutton said the decision should be between employers and their workers.
"The employers are the ones paying the wages and if they don't believe that it is possible within their business for that person to work from home, that's the decision that should be made," he told Today.
"I understand people want flexibility. Nobody wants to get on a train in the morning (and) go to work. I get that.
"If possible, that's great, but ultimately the employer is the one that has to make the call there."
Ms McManus warned expectations about working from home could see women negatively affected as they juggle their jobs with childcare or other unpaid labour.
People could also miss out on career opportunities because they're not being seen in the office.
She said flexible arrangements could also help workers deal with the cost of living crisis, helping them to save money on their commute amid skyrocketing petrol prices.
Prime Minister Anthony Albanese has said it's up to workplaces to decide their working-from-home arrangements.
Mr Albanese also said the impact of the current winter wave, driven by infectious Omicron sub-variants, was likely to be similar to that of the summer wave earlier this year.
Based on modelling, it's expected the third Omicron wave will peak in August and wane by September.
