A surprise move by Sen. Charles E. Schumer, (D-N.Y)., to block the Dubai ports deal caused a ruckus on the Senate floor and temporarily derailed debate. The Senate was in the midst of debating an amendment on the lobbying bill when Schumer said he wanted to talk about that amendment. But in a move that blindsided Republicans, Schumer instead offered an amendment to bar the sale. The Schumer amendment prohibits any company owned or controlled by a foreign government that recognized the Taliban as the legitimate government of Afghanistan from 1996-2001 from owning or operating U.S. ports. If passed, the acquisition by DP World, a company controlled by the United Arab Emirates, of a British company over operations of six major U.S. ports would be blocked. Republicans immediately stopped work and go into a quorum call. Republican leaders began signing a cloture petition in an attempt to limit debate and deny Democrats much opportunity to offer many amendments to the lobbying bill. Frist also threatened to "fill the tree" with amendments so that Democrats could not offer any substantive amendments if Schumer did not back down. Cloture is a proceedure used by the majority to end contentious debate. Cloture is traditionally used to end a filibuster, but can also be used even if there is no filibuster underway, to ban non-germane amendments. Normally, 60 senators must vote to invoke cloture. But ending debate on a formal Senate rules change requires two-thirds of those present and voting — 67 if all senators participate. If cloture wins, 30 additional hours of debate are allowed prior to voting, but they are rarely used. If cloture fails, debate would continue without limits. Instead, the bill is usually set aside. "Filling the tree" - Both the House and the Senate have rules mandating only amendments in the first and second degree are permitted. An Amendment Tree refers to the diagram used to plot the inter-relationship between amendments. "The tree" helps members keep track of how many amendments are pending,and how many may still be offered. Frist announced this morning that a cloture vote will take place at 2:15 today.