WBRZ - Baton Rouge

WASHINGTON - Republican Sen. David Vitter says he will block President Barack Obama's nominee to head the Labor Department until he gets a response to his letter complaining about the enforcement of voting rights laws in his home state of Louisiana.

Vitter's comments came just hours after Obama formally nominated Thomas Perez to the labor post. Perez currently heads the Justice Department's Civil Rights Division, which enforces voting rights laws.

The Louisiana Republican senator says that under Perez, the Justice Department sent undercover investigators to Louisiana to make sure state welfare offices encouraged recipients to register to vote. But he contends the department made no effort to enforce laws that require purging ineligible voters from the rolls.

A White House spokesman declined to respond to Vitter's threat.