BERLIN - Germany and Switzerland scrambled on Friday to salvage a landmark deal on taxing secret offshore accounts after the main German opposition party raised 11th hour objections to a compromise plan it branded full of "loopholes". BERLIN, March 30 (Reuters) - Germany and Switzerland scrambled on Friday to salvage a landmark deal on taxing secret offshore accounts after the main German opposition party raised 11th hour objections to a compromise plan it branded full of "loopholes". Germany and its tiny Alpine neighbour want to conclude by this weekend a pact that would protect Switzerland's tradition of banking secrecy -- cornerstone of its $2 trillion financial services industry -- by taxing wealthy Germans' Swiss accounts and levying a high interest rate on undeclared money. But Chancellor Angela Merkel's centre-right coalition needs the backing of states controlled by the opposition Social Democrats (SPD) to ensure the tax deal wins approval in Germany's upper house, the Bundesrat. SPD state premiers, who blocked an original deal last year as too lenient to tax dodgers, discussed concessions proposed by the Swiss on Thursday but decided they did not go far enough. "We still have big problems with this agreement," Hannelore Kraft, SPD premier of North Rhine-Westphalia, Germany's most populous state, told the Bundesrat.