The House Judiciary Committee issued a subpoena Friday requiring the Department of Homeland Security to hand over the names of thousands of illegal immigrants who were arrested by local authorities over the last three years but not deported by immigration officials.

The subpoena is the latest volley in a contentious debate between House Republicans and the Obama administration over its immigration policy, which makes deportation of illegal immigrants with criminal records a priority.

Rep. Lamar Smith (R-Texas), chairman of the House Judiciary Committee, estimates that more than 300,000 illegal immigrants were arrested and fingerprinted at local jails between October 2008 and April 2011 but were not taken into custody by U.S. Immigration and Customs Enforcement agents because they had committed “low-level” crimes.