Almost 110,000 WA families stand to lose the Schoolkids Bonus as the Federal Government this week begins what it hopes will be the last round of payments.
Labor will enlist parents this week as part of a campaign to pressure the Government to keep the bonus, arguing it gives families help when they face big back-to-school bills.
The bonus is $820 a year for each child in high school and $410 per child in primary school for almost 1.3 million families eligible for Family Tax Benefit A.
It is paid in two instalments - in January and July.
The Government wants to axe the bonus as part of the repeal of the mining tax, which funds the payment, but Labor and the Greens plan to block the move in the Senate.
Opposition Leader Bill Shorten, who returns from leave today, said scrapping the bonus was a "savage cut" for families struggling with the cost of living.
"If Tony Abbott gets his legislation through the Senate, the January Schoolkids Bonus to families will be their last," Mr Shorten said.
"It means families will find it much more difficult to pay for those important things like schoolbooks and uniforms."
The Opposition will highlight the looming abolition of the bonus as more hip-pocket pain for families after the Government's approval for the biggest rise in private health insurance premiums in a decade and a suggested $6 co-payment for bulk-billed doctors' appointments.
But Finance Minister Mathias Cormann said spending on the Schoolkids Bonus was money the Government did not have.
"Borrowing money to give it away, forcing today's schoolchildren to pay it back with interest through higher taxes later is just wrong and not in their interest," Senator Cormann said.
"The Schoolkids Bonus is another Labor spending promise linked to their failed mining tax, which hasn't raised any meaningful revenue."