McClellan told CNN Friday he would testify if asked.
Rep. Robert Wexler, D-Fla., said Friday McClellan would offer valuable information about several issues the House Judiciary Committee is investigating, CNN reported.
Among its investigations into President George Bush's administration are the use of pre-war intelligence, whether politics was why eight U.S. attorneys were fired and the outing of CIA operative Valerie Plame Wilson, Wexler said.
In his memoirs, McClellan wrote that Bush told him he authorized leaking Plame Wilson's identity to the media.
"The administration has always called for different kinds of privileges to avoid their officials testifying, but because McClellan has put all this information in a book, these privileges, I do not believe, would be available to the administration, so we would have a free flow of information," said Wexler, a senior member of the Judiciary Committee.
Bush spokeswoman Dana Perino said Friday the White House indicated it could invoke executive privilege to prevent McClellan from testifying, but it has not decided whether it would.