Congressional Democrats are demanding that the Trump administration explain how it will improve Obamacare’s insurance exchanges, after a federal watchdog found current efforts lacking, buttressing their case that the administration is sabotaging the health law.

“The nation’s health department, which has the self-identified objective of ‘improving Americans’ access to health care,’ should not be working against the interests of patients and families and their goals of obtaining quality, affordable health insurance,” the lawmakers wrote in a letter Monday to Health and Human Services Secretary Alex Azar and Centers for Medicare and Medicaid Services Administrator Seema Verma.