Americans are expected to see skyrocketing health care prices as the open enrollment period for insurance through the Affordable Care Act marketplace begins on Saturday.

About 24 million people buy health insurance through the marketplace, the majority of whom used to receive tax credits to lower the monthly price of insurance.

Without credits, the monthly cost could rise by 114% on average, according to health research nonprofit KFF. This could mean an extra $1,000 a year, and in some cases much more.

Democrats have demanded the healthcare subsidies, which expire at the end of the year, be extended in exchange for ending the month-long federal government shutdown.

Republican leaders have argued the health insurance issue should be dealt with separately, and after the government reopens. Though some conservative lawmakers have expressed concerns with the subsidies ending.

For those who have previously made use of the tax credits, the new costs could be a shock.

Stacy Cox and her husband, who are small business owners in Utah, were paying $495 (£376) a month for health insurance.

Ms Cox said that without the tax credits, their monthly premiums are estimated to rise to $2,168, a 338% increase.

“It’s horrific to actually see real numbers,” she said.

If the subsidies are not extended, Ms Cox said she and her husband will cancel their health plan and buy some type of emergency insurance, which would not cover any of their routine and preventative health care costs.

The back-up plan is worrying for Ms Cox, who has an autoimmune disease, and her husband, who has hereditary cardiovascular disease.

“It’s horribly stressful, because what I know is that the emergency plan is not going to cover what I need,” she said.

Experts say that about seven million people like Ms Cox are expected to stop buying health insurance through the marketplace if the tax credits end. Of those, around four to five million are expected to lose health care coverage altogether because they won’t be able to find other means, some experts suggest.

Lawmakers remain at an impasse over the issue, as they enter the second month of the government shutdown.

Democrats are seeking to renew the subsidies and reverse steep cuts President Donald Trump made to Medicaid, the government-run programme which provides healthcare insurance for low-income adults, children, pregnant women, elderly adults and people with disabilities.

Some Republican lawmakers have criticised the subsidies as a part of Obamacare legislation that they do not support.

But at least a few conservative lawmakers have said they want the tax credits to continue, including Trump ally Marjorie Taylor Greene, who has said she is “absolutely disgusted” by the subsidies ending.

Americans were also facing the possibility of a suspension of food aid used by more than 40 million people, because of the government shutdown.

But judges on Friday ruled that the Trump administration must pay for the Supplemental Nutrition Assistance Program (SNAP) benefits using emergency funds.

President Donald Trump reacted to the legal decision via Truth Social on Friday, saying: “our government lawyers do not think we have the legal authority to pay SNAP with certain monies we have available, and now two Courts have issued conflicting opinions on what we can and cannot do.

“I have instructed our lawyers to ask the Court to clarify how we can legally fund SNAP as soon as possible,” he said.