Former President Bill Clinton's office called the House Judiciary Committee's chief Republican counsel to decline an invitation by Rep. Lamar Smith to appear before a committee hearing this testify on presidential pardons.

The committee's minority part spokeswoman Beth McGinn told FOX News that a woman from Clinton's office kindly told the GOP committee staff that the former president would "not be able to testify because he will not be in D.C. that day."

Smith, R-Texas, had invited Clinton as his expert witness at a House Judiciary subcommittee hearing on executive branch authority to issue pardons. The question over the use of pardons has come up with the recent conviction of former White House aide I. Lewis "Scooter" Libby on perjury and obstruction of justice charges.

Clinton was embroiled in controversy over more than 100 pardons he issued on his last day in office more than six years ago, but the latest debate has Smith, the top-ranked Republican on the committee, calling the hearing nothing more than partisan politics aimed at President Bush.

"The Judiciary Committee should focus its energy on issues Americans care about — reducing crime, stopping illegal immigration and fighting terrorism — not harassing a president for partisan political purposes," said Smith, referring to the current administration in a statement released to FOXNews.com.

McGinn said the letter to Clinton was in response to an onslaught of partisan investigations into executive branch powers. Another upcoming hearing will be looking into the reach of executive privilege, which is the broad claim of separation of powers between Congress and the White House used to fend off congressional probes.

FOX News' Molly Hooper and Gregory Simmons contributed to this report.