The head of Austria's state railways has been overwhelmingly endorsed by his party as the country's next chancellor ahead of a meeting that will formally nominate a candidate.

That meeting is scheduled for Friday. But by Thursday, Social Democrats from eight of Austria's nine provinces announced their backing for railways head Christian Kern, while another potential candidate announced he was out of the running.

Werner Faymann, Austria's previous leader, bowed out earlier this week, leaving the Social Democrats smarting from a string of electoral losses to the right-wing Freedom Party and split between proponents and opponents of Faymann's hard-liner migrant policies.

The Social Democrats share the government coalition with the centrist People's Party. That party has signaled that it will accept only a Faymann replacement who backs tough migrant restrictions.