German eurosceptics a new threat to Merkel as election looms
* Support for AfD rises to record 4 percent in new poll
* AfD could hurt Merkel's shot at centre-right majority
* YouGov survey shows Germans back many AfD policies
BERLIN, Sept 4 (Reuters) - Support for a new anti-euro party has risen to a record high of 4 percent weeks before Germany holds an election, raising the possibility it could win seats in parliament and hurt Angela Merkel's chances of forming another centre-right coalition.
A poll by Forsa for Stern magazine showed the Alternative fuer Deutschland (AfD) within 1 point of the threshold needed to enter the Bundestag lower house.
Some experts believe that polls understate support for the AfD because voters may be embarrassed to admit they back the party, in part because German media has focused on its links to the far-right.
Were the AfD to make it into the Bundestag, it would make it more difficult for Chancellor Merkel to win another centre-right majority with the business-friendly Free Democrats (FDP), increasing the chances of a "grand coalition" between her conservatives and the centre-left Social Democrats (SPD).
Eurosceptic parties have flourished in neighbouring countries like France, Austria and the Netherlands, frequently mixing their disdain for the single currency with an anti-immigration message.
But in Germany, where support for parties with xenophobic tendencies remains low because of the legacy of the Nazis, there was no mainstream political movement advocating an end to the euro until the AfD was founded earlier this year.
In recent months, polls have shown support for the party hovering in the 2-3 percent range, as the easing of the euro zone crisis undermined the AfD's message.
But last month German Finance Minister Wolfgang Schaeuble thrust the euro back onto the campaign agenda by saying Greece, which has already received two bailouts totalling 240 billion euros, would require a third rescue.
A YouGov Deutschland survey this week showed widespread support for some of the AfD's policies, such as their rejection of further rescues and proposal to limit the single currency to a small group of "more similar countries".
Merkel remains very popular with a broad spectrum of Germans less than three weeks the Sept. 22 vote. But her conservatives and their FDP allies have a wafer-thin lead over the combined opposition, polling 45 percent versus 43 percent for the SPD, Greens and hard-line Left.
That majority would vanish altogether if the AfD made it over the 5 percent threshold.
The Forsa poll also showed that the SPD had been boosted by its candidate Peer Steinbrueck's competent performance in the only TV debate of the campaign on Sunday. He followed up with a spirited attack on Merkel in the Bundestag on Monday.
"Now it's getting exciting," said top-selling daily Bild, which praised the SPD challenger for finally showing himself "confident and feisty" in parliament on Tuesday.
Steinbrueck, finance minister under Merkel in the "grand coalition" she led between 2005-2009, accused her of "burning bridges" by calling the SPD "unreliable" on Europe.
The SPD and its Greens allies have supported her in parliament on all the major euro crisis votes since the first Greek rescue package in May 2010.
The AfD, led by eurosceptic academics and journalists, has seized on this broad cross-party consensus for euro rescue packages to argue that they are the only alternative for voters who disagree with the bailouts.
As Europe's biggest economy, Germany has provided the largest share of rescue loans to countries like Greece, Portugal, Ireland and Cyprus.
(Reporting by Stephen Brown; Editing by Noah Barkin)