US president Barack Obama's nominee as health secretary, Tom Daschle, has withdrawn from the post because of tax problems.
Mr Daschle, a former Democratic leader in the Senate and a key Obama adviser named to lead sweeping healthcare reforms, withdrew from consideration after tax errors caused him to pay $US140,000 in back taxes.
Earlier on Tuesday, Mr Obama's nominee to become the first US "chief performance officer" to oversee government budget and spending also withdrew her name from consideration because of tax questions.
Nancy Killefer, nominated to oversee budget and spending reform, withdrew citing personal tax issues that "could be used to create exactly the kind of distraction and delay" the administration should avoid.
Ms Killefer was the third Obama nominee to face income tax questions. Treasury Secretary Timothy Geithner's nomination faced criticism over his late payment of $US34,000 in self-employment taxes. He was eventually confirmed.