Berlin  - Support for Germany's Social Democratic Party (SPD) fell to a record low, in an opinion poll published Wednesday, as the number of voters saying they would vote for the nation's hardline Left Party hit a new high.

German pollsters Forsa said in a poll published in the weekly Stern magazine that support for the SPD, a member of Chancellor Angela Merkel's ruling coalition slumped three-percentage points over the last week to just 20 per cent.

The continuing sharp fall in support for the SPD has helped to fuel a debate in the country whether party chief Kurt Beck should lead the party into next year's national election as Chancellor candidate.

At the same time, support for the Left Party edged up to 15 per cent with the rise of the Left Party, which has its origins in former communist East Germany, sparking political tensions in the SPD.

Beck has insisted that the SPD has no plans for a tie-up with the Left Party.

However, Wednesday's poll appears to show Beck's endorsement last week of university professor Gesine Schwan as a challenger to President Horst Koehler in an election also to be held next year appears has raised fresh doubts about a possible a link up between the SPD and the Left Party.

To win the largely ceremonial post of German president, Schwan would possibly need a broad backing, including from the Left Party.

In the Forsa poll, Merkel's Christian Democratic Union garnered 36 per cent, while the liberal Free Democratic Party scored 13 per cent and the environmental Greens obtained 12 per cent.

If the Forsa poll results were repeated at the next election, Merkel could abandon her awkward coalition with the SPD and forge new government with the Free Democrats, the CDU's preferred coalition partner. (dpa)