Looks like facing British Parliament could be the warm-up act for Bob Diamond. The former Barclays CEO—who resigned last week amid allegations that his bank fixed British mortgage rates—could be called to testify before Congress, sources said on Wednesday. The Senate banking committee and the House financial services committee are both reportedly gathering information about the scandal and could call Diamond to testify after the summer recess. Senator Tim Johnson, chairman of the Senate banking committee, said on Tuesday that they will be questioning Federal Reserve chairman Ben Bernanke and Treasury Secretary Tim Geithner on the Barclays scandal. The U.S. Justice Department is already investigating the scandal.