Republican presidential nominee Donald Trump proposes to allow families to deduct the cost of childcare expenses from income taxes, his campaign said, a move aimed at bolstering his support among women voters.

Trump was to lay out the plan in a Tuesday evening speech in the Philadelphia suburb of Aston, Pennsylvania, his latest attempt to construct a policy framework that he would use for governing if elected over Democrat Hillary Clinton.

Trump was to be introduced at the event by his daughter, Ivanka, who has championed the issue of childcare as an influential voice in his campaign. She told reporters on a conference call that she was involved in developing the plan.

"I'm very passionate about this," she said.

Trump's support among women voters has lagged. Overall, he has risen to a more competitive position against Clinton in national opinion polls and in battleground states where the election is likely to be decided.

Polls show the race tightening in the crucial state of Pennsylvania. A Quinnipiac University poll last week said Clinton led 48 percent to 43 percent for Trump there, a reduction from her 10-point lead a month ago.

Trump's plan would change the tax code to let parents deduct from their income taxes childcare expenses for up to four children and elderly dependents, his campaign said.

It would be available for individuals earning less than $250,000 a year or under $500,000 for couples filing jointly.

Trump campaign officials did not detail the overall cost of the program. A senior official said it would be part of Trump's plan to overhaul the tax code and would end up not adding to deficit spending in the federal budget.

Trump would offer childcare spending rebates to lower-income taxpayers through the existing Earned Income Tax Credit. The campaign said this could mean tax rebates as high as $1,200 for eligible families each year.

Trump also would create new Dependent Care Savings Accounts to allow families to set aside money "to foster their children’s development and offset elder care for their parents or adult dependents," the campaign said. Individuals could contribute up to $2,000 a year tax free.

The New York businessman also is proposing guaranteed six weeks of paid maternity leave. He would accomplish this by amending the existing unemployment insurance that companies are required to carry.

The benefit would apply only when employers do not offer paid maternity leave, and would be paid for by offsetting reductions in the federal unemployment insurance program so that taxes are not raised.