Unless Congress takes legislative action by the end of the year, Fannie Mae and Freddie Mac’s “unlimited” pipeline of cash support from the U.S. Treasury will be significantly dialed back, a paper by Deutsche Bank cautions. Although agency mortgage market observers have assumed that the Treasury will extend the taxpayers’ unlimited line of credit to the GSEs before the Dec. 31 deadline, a close reading of the authorizing legislation suggests that the Treasury may not be able to extend unlimited support without the approval of Congress, noted Deutsche Bank.