BERLIN, April 5 (Reuters) - The leader of Germany's opposition Social Democrats (SPD) said on Thursday his party would vote against a revised deal with Switzerland on taxing secret offshore accounts when the agreement goes to Germany's Bundesrat upper house.
Earlier on Thursday, the German finance ministry said Berlin and Berne had signed an amendment to a deal sealed in September of last year which toughens terms for tax dodgers.
SPD-led states had threatened to block the original deal in the Bundesrat. Some but not all of their demands were met in the revised agreement.
"It will fail a second time because the SPD-led states will not go along with it," SPD Chairman Sigmar Gabriel told reporters.
Conservative Chancellor Angela Merkel needs opposition support to get the deal through the upper house. It is widely expected to go to the Bundesrat after the summer parliamentary recess. (Reporting by Holger Hansen, writing by Madeline Chambers, editing by Noah Barkin)