By Francois Murphy, Shadia Nasralla and Kirsti Knolle
VIENNA (Reuters) - Austrian Chancellor Werner Faymann resigned on Monday, bowing to a revolt from inside his Social Democratic Party after it suffered a humiliating electoral defeat to a far right buoyed by Europe's migration crisis.
Faymann's surprise announcement marks the fall of a political survivor adept at compromises and about-faces that angered his party's base in his more than seven years in power.
While the Social Democrats' popularity has been waning for years, the rising tide of populism that has carried anti-immigrant parties in countries like Germany and Sweden during the migration crisis hastened his departure.
"Do I have full cover ..., strong support within the party? I must say the answer is no," Faymann, 56, said in a statement.
"I draw the consequences from this low level of support and step down from my positions as party leader and federal chancellor."
Vice Chancellor Reinhold Mitterlehner, who heads the conservative People's Party that rules in coalition with the Social Democrats, said he saw no need for a snap election after the announcement, APA news agency reported.
"For us it was a big surprise as we believed the personnel debate at the Social Democrats had been done," conservative Finance Minister Hans Joerg Schelling told reporters in Brussels. Markets, however, shrugged off the news.
As the anti-immigration Freedom Party is leading in opinion polls on more than 30 percent, the Social Democrats have little interest in a general election being held before the next one due in 2018, as they would most likely lose the chancellorship.
With President Heinz Fischer, a former Social Democrat, in office until early July, a Social Democrat is likely to take over from Mitterlehner, who will meanwhile run the government on an interim basis.
The Social Democratic Party (SPO) leadership set about finding a successor for Faymann at a meeting on Monday, and asked the veteran mayor of Vienna, Michael Haeupl, to take over as party leader for the time being.
"I am not chancellor and have no intention of becoming it," Haeupl told a news conference after the meeting.
SUCCESSOR NEXT WEEK
Haeupl said the leadership's pick to succeed Faymann would be announced on Tuesday next week and then submitted to Fischer to be appointed as chancellor. A party conference planned for June 25 should then approve that choice as party leader.
Two names have been widely mentioned as the most likely successor: Christian Kern, the head of Austrian rail operator OBB, and Gerhard Zeiler, former head of public broadcaster ORF and now president of Turner International (N:TWX).
Faymann paid the price for the first round of Austria's presidential election two weeks ago, when the Freedom Party's candidate came first on 35 percent and neither ruling party nominee made it into the May 22 run-off.
After the election, which produced the worst combined result for both of the mainstream parties since Austria's president became directly elected in 1951, opposition among Social Democrats grew into open revolt. Faymann was even jeered at a May Day rally.
Any new leader will have to try to heal rifts in the party over issues such as the government's growing restrictions on immigration and asylum, which have been widely interpreted as a late attempt to mimic populist far-right policies.
Austria took in around 90,000 asylum seekers in 2015, more than 1 percent of its population and many fleeing war and poverty in the Middle East and beyond.
It has since said it cannot cope with as many migrants in future, and acted to stop the influx through measures such as shutting down the main migrant route into Europe, in coordination with its Balkan neighbours.
The party is also divided over whether it should reverse a self-imposed ban on forming national coalitions with the Freedom Party. Faymann repeatedly said he opposed such a move.