As many as 10,000 Australians are expected to be affected by a nationwide strike on Thursday afternoon as childcare workers demand better pay.

More than 3000 early educators stopped work at 3.20pm on Thursday — the time the United Voice union claims staff start working for free as some wages can be low as $21 an hour — meaning thousands of children will need to be picked up early.

It is expected to be the biggest walk-off by childcare workers in Australian history and is the second this year after a protest in March failed to influence the federal budget.

The workers are calling on the federal government to improve childcare pay rates, arguing $21 an hour is significantly less than what men with equivalent qualifications earn in other sectors.

Childcare workers spend up to four years studying to acquire the relevant qualifications for the position.

The union is calling for a 35 per cent pay rise.

United Voice assistant national secretary Helen Gibbons said any families expected to be affected by the walk-off should have been notified by their childcare centre in advance.

She said about 180 people leave the industry each week due to struggles in paying the bills.

“It is one of Australia’s most poorly paid professions. Educators are only paid half the average wage,” Ms Gibbons said.

“Educators’ pay doesn’t come close to matching the highly skilled and professional nature of their work.

“Equal pay needs to be a national priority – in 2017 paying women less than men is not acceptable.

“In this day and age, in 2017, it’s just not okay to undervalue the work they do.”

Ms Gibbons added that the workers would “continue to stand up and speak out”.

“We will continue to escalate from here. We are not going away,” she said.

Many also felt their low pay stemmed from their jobs being seen as “women’s work”, done for the love of it.

There were mixed reactions from families, with some Australians surprised by the low earnings of early educators given the high cost of childcare.

“Striking over what? I don’t understand why they are striking against the government. As most childcare is privatised, shouldn’t they protest their company? The cost of childcare is absolutely ridiculous as it is,” one Facebook user said.

Meanwhile, others threw their support behind the strikers.

We're getting so much support coming through! Everyone agrees that #EqualPay must happen NOW! #BigStepsNOW #OzEarlyEd #auspol #ausunions pic.twitter.com/QMFEKw6bbM

— Big Steps Campaign (@BigStepsUWU) September 7, 2017

“Totally support the workers! This industry needs a serious overhaul,” another said.

“Centre owners have parents bent over a barrel, charging exorbitant fees, passing on peanuts to their staff, under-resourcing their centres, and drive around in Mercedes SUVs.

“Staff aren’t even paid for mandatory training, and most are expected to compete it in their own time on top of that. Absolute joke.”

Melbourne parent Belinda Goss said childcare workers deserved to earn much more.

“Nothing used to annoy me more than receiving a rate rise notice because that money was not going to the carers looking after my child, it was going to either the centre or the government,” she wrote on Facebook.

“These people bring up our kids while we’re at work. They spend 10 hours of the day with our children. They care for them, feed them, change nappies, entertain them, educate them and even love them.

“The money they get is disgraceful and they deserve so much more.”

Meanwhile, former early educator and parent Christie Dowler said that in her years of working in childcare she remembered just one pay rise.

“But how many times did we see fees go up? Loads,” she wrote.

“Staff never were the reasoning for fee rises, we still worked bloody hard but no rise. I’ve often wondered who makes the money, definitely business owners not the staff.

“With all the regulations and expectations for this industry they deserve better money.

“I too am a parent and childcare is so expensive, but remember what these people do and how precious your little people are.”

– with AAP and ABC