Last week the Senate’s majority leader Harry Reid sought unanimous consent to proceed with the confirmation of Groves, who last month was chosen to lead the Census Bureau by President Obama and approved by the Senate’s Committee on Homeland Security and Governmental Affairs.

But the vote was blocked by minority leader Mitch McConnell, who said the nomination had not yet been cleared by Republican senators. Groves was a controversial choice because he has in the past advocated the use of sampling to adjust results for sections of the population which tend to be undercounted – and which also tend to be Democrat voters.

However, Groves has highlighted the importance of an “objective, nonpartisan” Census Bureau. He said that decisions made before his nomination meant no infrastructure was in place for statistical adjustments to be implemented in time for the 2010 count anyway.

A spokeswoman for Senator Reid said the Democrats would like to move forward with the confirmation as soon as possible. “We are still working to get an agreement with Republicans,” she said.

A Democratic aide quoted on GovExec.com said the Republicans’ hold on the confirmation vote could be put down to the short time in which the matter came to the Senate floor, giving them little time to examine the nomination.