The strike will last 24 hours with more than 60 preschools expected to shut fully or partially for the day.

The Australian Education Union's Victorian branch will hold a rally in the morning at the Athenaeum Theatre before moving on to the steps of the Victorian Parliament.

Almost 15 months has passed since negotiations began between the union and Early Learning Association and Municipal Association of Victoria, which represent preschools.

The union's Victorian president Meredith Peace said preschool teachers were seeking a deal that would achieve pay parity with their primary school counterparts. Last month Fairfax Media reported the union had rejected a 2.25 per cent pay increase.

Ms Peace said it had been more than 10 years since preschool teachers had been on strike. She said preschool teachers were paid between 5 per cent and 9 per cent less than school colleagues, respectively, at the beginning and top of their salary scale.

Ms Peace said the union was willing to continue its industrial action after the strike. "Our council will continue to make decisions about further industrial action if the employer groups and government sitting behind them aren't prepared to to make a fair and decent offer," she said. "We'll continue to campaign."

Early Learning Association Australian chief executive Shane Lucas said preschools had been told to close if they were unable to find sufficient replacement staff. "If there's a shadow of a doubt that duty of care is a concern we'd encourage them to close," he said.

Mr Lucas accused the union of using the pay dispute to put pressure on the Victorian government. "At the end of the day the union is undertaking a political campaign in the context of a state election."

He said the association had made a revised offer earlier this month that would have ensured parity for preschool teachers and primary school teachers over four years. Mr Lucas said the union had also rejected that offer.

In an email to preschools Mr Lucas said the association's most recent offer was a "considered response made in good faith" to address the union's demands within the funding available from the government.

"We believe our new proposal substantially addresses the union's concern to achieve salary parity between early childhood education teachers and their colleagues in the primary school system," he wrote.

That offer included a new proposal on workloads and classifications, he wrote.

But the union insisted the latest offer would not result in parity for preschool teachers. Ms Peace said the proposed changes to classifications were also unfair.

Mr Lucas said union members would decide whether to strike and "we respect individuals right to make that decision".

He told Fairfax Media that the state government funded the majority of kindergarten teachers' salaries while parent fees and fundraisers accounted for the remainder. The state government declined to comment.

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The following list, supplied by the Australian Education Union, may not include other preschools that are fully or partially closed.

Donvale Preschool

Blossom Park Kindergarten

Montessori Early Learning Centre

Appletree Hill Preschool

Grange Road Sandringham

Pinewood Preschool

Greenhills Preschool

Red Cliffs and Nangiloc Kindergartens, Mildura

Lergerberg Preschool

Turner St Kindergarten

Bentleigh West Kinder

Laharum Preschool

Alamanda Kindergarten

Grace Park Preschool

Kallista Kindergarten

Greenbrook Kindergarten

Jells Park

Monbulk Kindergarten

Kingsway Preschool

The Merrell Kindergarten

Albert Park Preschool

Yarralea Children's Centre

Sydenham

Lalor East Preschool

JJ McMahon Memorial Kindergarten

Langwarrin Park Preschool

Apex Kindergarten

Bowerbird Preschool

Ashwood Memorial Kindergarten

Moyhu Preschool

Mentone Preschool

Chirnside Park

Ballam Park Preschool

Altona Kindergarten

Fawkner Kindergarten

Broadmeadowns Kindergarten

Lady Forster Kindergarten

Eversham Road Preschool

Alfred Nuttall Kindergarten

South Sunshine Kindergarten

Oakleigh Primary School Kindergarten

Bentons Square Kindergarten

Fordham Avenue Kindergarten

Rowen St Kindergarten

Beleura Hill Kindergarten

Dromana Preschool

Farm Road Kindergarten

Hollins Children's Centre Pakenham

MILDURA AREA CLOSURES

Nangiloc and District Preschool

Red Cliffs Kindergarten

Irymple Kindergarten

St Margaret's Preschool

Pasadena Kindergarten

De Garis Kindergarten

Kathleen Kelly Kindergarten

Merbein Kindergarten

Mildura south Kindergarten

BALLARAT AREA

Group of members travelling by train to Melbourne Rally

At least 7 closures –

Linda Brown Preschool

Creswick Preschool

Bakery Hill Preschool

Sebastopol Kindergarten

Woady Yaloak Kindergarten

Fidelity Kindergarten

Jubilee Kindergarten