BERLIN (Reuters) - Support for Germany's opposition Social Democrats (SPD) has jumped since their victory in a regional election, a poll showed, highlighting the increased domestic pressure on Chancellor Angela Merkel as she battles the euro zone crisis.
The INSA survey, published by Bild newspaper on Tuesday, put the centre-left SPD on 32 percent, up three percentage points in just one week. Merkel's ruling Christian Democrats (CDU) were just ahead on 33 percent, down one percentage point.
Also worryingly for Merkel, her Free Democrat coalition partners were at 4 percent, below the 5 percent threshold required to gain seats in parliament, while the SPD's favored coalition partner, the Greens, stood at 14 percent.
Earlier this month the CDU suffered a humiliating defeat at SPD hands in Germany's most populous state, North Rhine-Westphalia (NRW), where it saw its support tumble to 26 percent from 35 percent in 2010.
The result prompted Merkel, who hopes to win a third term in national elections due in September 2013, to sack her environment minister after he led a poor election campaign.
The SPD's advances, along with Socialist Francois Hollande's victory in France's presidential election this month, have emboldened the party to take a more confrontational approach at a time when Merkel needs their support to push an EU "fiscal compact" through the German parliament.
Merkel, under pressure from Hollande and some other European leaders abroad to ease up on tough austerity policies to tackle the euro debt crisis, is also trying to resolve embarrassing conflicts within her centre-right coalition over childcare subsidies and data protection.
The INSA poll, conducted on May 18-21, also showed the maverick new Pirate Party winning 8 percent and the Left party 6 percent.
(Reporting by Alexandra Hudson, editing by Gareth Jones)