The composition of President Obama's second term Cabinet became clearer Wednesday, with Labor Secretary Hilda Solis resigning and three other members of the president's team deciding to stay on amid concerns about diversity in Obama's inner circle.

Solis, a former California congresswoman, said she was leaving after leading the department during the economic storms of the first term. She was the nation's first Hispanic labor secretary and one of five female Cabinet secretaries. The timing of her departure was a bit of a surprise.

A White House official said three Cabinet members -- Attorney General Eric Holder, Health and Human Services Secretary Kathleen Sebelius and Veterans Affairs Secretary Eric Shinseki -- would stay on. It would ensure diversity among the president's leadership team -- Holder is black, Sebelius is a woman and Shinseki is of Japanese-American descent.

Some Democratic women have raised concerns that the "big three" jobs in the Cabinet -- State, Defense and Treasury -- will be taken by white men. Democratic Sen. John Kerry of Massachusetts has been tapped as the next secretary of state; former Nebraska Sen. Chuck Hagel, a Republican, was picked to run the Pentagon and White House Chief of Staff Jacob Lew is expected to be named treasury secretary.

The White House is expected to announce more members of Obama's Cabinet in the coming weeks, giving the president a chance to present a team that reflects the diverse coalition of women, Hispanics and minorities that helped give him a second term.

Obama said Solis was a "tireless champion for working families" and had been a key member of his economic team during a first term marked by efforts to rebound from the recession. She won praise from labor unions for an aggressive enforcement of wage and hour laws and safety regulations, but business groups criticized her for not taking a more cooperative approach.

Solis is expected to return home to California to run for a seat on the Los Angeles County Board of Supervisors.

OBAMA: 'NO BACKUP PLAN' FOR DEBT CEILING

The White House is dismissing suggestions to sidestep Congress to meet the nation's debt obligations, declaring that it is Congress' responsibility to pay the bills of the United States.

President Obama's stand that he will not negotiate over raising the nation's borrowing limit and Republican demands that a debt ceiling vote be linked to spending cuts have prompted a creative outburst of alternatives. Democrats have urged Obama to raise the debt ceiling without going through Congress. But White House spokesman Jay Carney said Wednesday: "There is no plan B. There is no backup plan. There is no alternative to Congress raising the debt ceiling."

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