Austrian railway chief Christian Kern stands on the “Bahnorama” observation tower during its official opening in Vienna, Aug. 19, 2010. Lisi Niesner/Reuters

The head of Austria's rail operator, Christian Kern, is set to become the country's next chancellor after the other main contender for the post of Social Democratic Party (SPO) leader pulled out of the race and said the whole party backed him.

Werner Faymann stepped down as chancellor this week, bowing to a revolt inside the SPO after it suffered a heavy defeat in the first round of a presidential election last month, in which the anti-immigration Freedom Party's (FPO) candidate came first.

Kern, who oversaw the mass transit of asylum-seekers to Germany from Hungary's border at the height of the migration crisis last autumn, was up against Gerhard Zeiler, a former head of national broadcaster ORF and now the president of Turner Broadcasting's international arm.

But Zeiler said on Thursday he would not run for the post of party leader and head of the coalition government, later adding that he and Kern had long agreed not to oppose each other.

"He will be a very good chancellor, a very good party leader, and he has the support of the whole party," Zeiler said of Kern in an interview with ORF after announcing his decision.

The SPO's leadership is due to formally choose its proposed successor to Faymann on Tuesday, but with its powerful governors of Austrian provinces due to meet on Friday morning, party heavyweights could make an informal announcement sooner.

Once the party makes its choice, Austrian President Heinz Fischer must approve the candidate for them to take office, and Fischer appeared to have already made up his mind.

"The man who is in the foreground is certainly the right one and has fulfilled his current duties well," Fischer, a former Social Democrat, told ORF during a visit to Berlin.

SPO branches in eight of Austria's nine provinces have already expressed support for Kern.

Kern, 50, took over the Alpine republic's state-run railway operator OBB in 2010. He previously served as spokesman for the SPO's parliamentary group and as a manager at Austrian hydropower utility Verbund.

Few details have emerged on his political leanings or likely policies, but speculation has begun about a reshuffle of SPO ministers, with several media outlets reporting those closest to Faymann would be purged.

The Finance, Foreign and Interior Ministries, however, are all headed by members of the SPO's junior coalition partner, the People's Party (OVP).

The OVP has made the continuation of their alliance conditional on Faymann's successor backing a tough, recently enacted asylum law, agreeing to cap a key benefit payment and negotiating an economic package with an element of deregulation.