Hungary's health minister asked for resignation in a letter addressed to the prime minister.
The premier's office in a statement confirmed Lajos Molnar's resignation as of April 6 and said until a new minister was confirmed, Agnes Horvath, health state secretary, would be leading the ministry.
Molnar has been health minister in Prime Minister Ferenc Gyurcsany's Socialist-led government since June 2006.
During the day, politicians from the opposition Christian Democratic Peoples Party have called on Molnar to resign while also calling on Gyurcsany to dismiss his health minister.
Hungary's government, since general elections last April, has implemented heavy austerity measures needed for the country to reach its budget deficit targets.
In the past few months, Hungary's governing coalition has introduced higher taxes, direct payments for some health care services and tuition fees for most university students. Subsidies for household energy use also have been cut and thousands of public employees dismissed.
The government's newly adopted health care reforms, including shutting down several key health care institutions nationwide, have stirred up controversy. But the prime minister's office, in its statement, reiterated that the government is sticking by its health reforms.
The statement of Gyurcsany's office did not reveal why Molnar resigned.
The health ministry Wednesday afternoon said its officials were holding consultations and were unavailable for comment.