Dusseldorf/Berlin, May 10 (DPA) German Chancellor Angela Merkel was facing the loss of her majority in the upper house of parliament, following the poor showing by her Christian Democrat (CDU) allies in a key state election.

In North Rhein-Westphalia, which as Germany’s most populous state contains around a fifth of all the country’s voters, the CDU lost some 10 percent of its support.

The CDU had governed in the state, in an arrangement mirroring the national government, with the liberal Free Democrats (FDP) since 2005.

The liberal Free Democrats’ result stayed flat at 6.8 percent, half a percent up on 2005, spelling an end to the coalition’s reign.

The result also means that the centre-right federal coalition in Berlin can no longer count on a majority in the Bundesrat, where the 16 state parliaments are represented.

The official count showed that the CDU had some 34.6 percent of the vote – the worst-ever result for the centre-right party in the state.

“It is a bitter evening for the CDU in North Rhein-Westphalia, and for me personally,” incumbent state premier Juergen Ruettgers said.

The vote came at a time of wide popular discontent with the federal government over its 22.4-billion-euro ($28.5 billion) contribution to the bailout of Greece, agreed last week in Berlin.

Merkel, who attended a ceremony to mark the 65th anniversary of the end of World War II in Moscow on Sunday, has spent several weeks attempting to explain to voters the necessity of the bail-out for the stability of the euro.

Critics accused her of attempting to delay the unpopular measures until after Sunday’s vote.

Her coalition must now prepare for harder compromise negotiations with Social Democrat and Green opposition at a federal level, if it hopes to push through controversial tax-cut programs, budget cutting measures and health-care reform.

The vote was seen as the first major electoral test for the national coalition, which has been plagued by infighting and sinking ratings since the general election in September 2009.

Voters, however, also appeared to show their discontent with Ruettgers, who became embroiled in a party donations scandal.

Local issues such as cuts in public spending and education played a pivotal role in the reverse for the CDU, analysts said.

“I personally bear the political responsibility,” Ruettgers said following the vote.

The big winners of the day were the Greens, who increased their share of the vote by six percent from 2005 to 12.1 percent.

Green party state leader Claudia Roth said that the election result was “the beginning of the end” for Merkel’s centre-right coalition.

The centre-left Social Democrats (SPD) were practically neck-and-neck with the CDU at 34.5 percent, making a Green-SPD coalition the core of a possible new government in the state, which suffers from a rusting industrial sector and unemployment of over 10 percent.

The state contains major cities such as Cologne and Dusseldorf, as well as former industrial powerhouses such as Bochum and Gelsenkirchen.

The SPD had dominated the heavily working-class state for 39 years before Ruettgers became premier in 2005.

Manufacturing jobs have been transferred overseas in recent years, and the collapse of General Motors’ subsidiary Opel has hit the region hard.

The radical Left party gained two and a half points to around 5.6 percent, bringing it over the 5 per cent hurdle to allow representation in the chamber. Other, smaller parties made up the final six percent.

Coalition negotiations will follow the final declaration of results.

While a majority CDU-SPD government is possible, SPD state party leader Hannelore Kraft said following the results that her preferred line-up was a coalition with the Greens.