Three leading Republicans asked Monday for figures on how much the federal government is spending on Obamacare subsidies, as the Obama administration announced double-digit rate increases for 2017.

House Energy and Commerce Committee Chairman Fred Upton asked the Centers for Medicare and Medicaid Services for estimates by Nov. 7 of the taxpayer dollars being spent on the subsidies, which are given to enrollees with low and moderate incomes.

While the administration has downplayed rising premiums by noting the availability of the subsidies, Republicans have sought to draw attention to the rate hikes to make their case that the Affordable Care Act isn't working well.

"While the administration continues to focus on premium 'affordability,' it ignores the undeniable fact that federal taxpayers are subsidizing these premium increases through tax credits," Upton wrote in a letter also signed by Reps. Joe Pitts and Tim Murphy of Pennsylvania.

The subsidies are available in income-based amounts for people not eligible for Medicaid and earning up to 400 percent of the federal poverty level. They're a major way President Obama's healthcare law ensures that the formerly uninsured can afford to get coverage.

The subsidies are sheltering a majority of marketplace enrollees from increasing costs, as insurers raise rates around the country. The Department of Health and Human Services announced Monday that consumers in most states will see their premiums increase by 22 percent on average.