WASHINGTON -- Advocates of what's come to be called the "talking filibuster" are closing in on the majority needed to reform the rules, according to a whip count compiled by The Huffington Post, based on interviews with Democratic senators and with reform advocates who have spoken with senators. Cross-checking the list with prior voting records and public statements indicates that Democrats could lock up as many as 52 votes by this week, when they are expected to introduce a rules reform package to be voted on in the new year.

An extraordinarily broad coalition of progressive and labor organizations is upping the pressure to include the provision in a package of rules reforms. The coalition of 48 liberal groups, Fix The Senate Now, sent a letter to Senate Majority Leader Harry Reid (D-Nev.) and his colleagues in leadership on Monday morning. A copy was provided exclusively to HuffPost and it calls for a variety of reforms, including the talking filibuster being pushed by Sen. Jeff Merkley (D-Ore.). Another far-reaching reform the group asks for is to put the onus on the minority to find 41 votes to block legislation, rather than forcing the majority to find 60.