Lawmakers in Haiti have rejected President Michel Martelly's pick for prime minister — a political blow for the newly sworn-in leader of the impoverished Caribbean nation.

The vote Tuesday was 42 – 19 against Daniel-Gerard Rouzier, with some accusing him of tax evasion, a charge he has denied. Others raised questions over his business dealings and citizenship.

Mr. Martelly, who took power a month ago, must now find a new candidate. And he must manage to win over members of former President Rene Preval's Unity party, which won a parliamentary majority this year in elections widely criticized by international observers.

Without a prime minister, Mr. Martelly has been unable to form a government to begin to tackle the extensive challenges facing his country.

Haiti was crippled by a January 2010 earthquake that killed more than 200,000 people and made one million others homeless. Hundreds of thousands of people still live in tent camps, and millions continue to rely on non-governmental organizations to meet their basic needs. Martelly also faces the political challenge of working with a legislature controlled by Mr. Preval's opposition party.

International donors have pledged billions of dollars in aid to help Haiti rebuild, waiting for the new government to take office before releasing it.

And even before the quake struck, Haiti was the Western Hemisphere's poorest country, and was plagued by political violence and lawlessness, corruption and natural disasters.