Executives and business experts expect major difficulties for the economy in a German state where the far-right Alternative for Germany (AfD) seems poised for victory in a keenly watched election on Sunday.

The main concerns involve investment and skilled workers from abroad, economist Monika Schnitzer told the Kölner Stadt-Anzeiger newspaper. "Given the party's election programme, it can be expected that if the AfD takes over the government, the state will become significantly less attractive as a location for skilled workers and companies."

Michael Hüther, director of the German Economic Institute (IW) think tank, took a similar view. "Anyone competing for foreign skilled workers must not strengthen a party that openly calls for their expulsion," he told the Rheinische Post newspaper.

An immigration policy based on the AfD's programme would be disastrous for Saxony-Anhalt, where the party is expected to secure a strong victory in Sunday's election, he said. There are concerns the party could secure enough support to govern on its own in the state.

Hüther added that, without immigration, demographic trends could cause the state's working-age population to shrink by around a quarter by 2045, leaving more than one non-working person for every person of working age.

Christian Bruch, chief executive of Siemens Energy issued an urgent warning on AfD energy policies in remarks to dpa. Their programme calling for a return to coal and nuclear power was bad for German industry and in some respects attacked democracy, he said.

"I consider that absolutely critical," he said. "Our company and our jobs in Germany depend on our ability to export, to attract international skilled workers to Germany, and on foreign investors being able to rely on political stability," Bruch said.

He noted that German domestic intelligence classified the AfD in Saxony-Anhalt as a "confirmed" right-wing extremist organization.

Bruch expressed disappointment that German politicians had failed to find compromises that most of the population could identify with, describing the situation as "absolutely critical."

He warned that other countries were undergoing rapid change and that the AfD was sending out a "dramatically wrong message" with its vision of returning Germany to past successes. "Nostalgic politics keeps setting us further back," he said.

The AfD's energy policies were "not sensible" in a highly interconnected Europe, he said.

In recent months, leading business executives have repeatedly warned about the AfD's economic plans. "Populist parties claim to have simple answers," Deutsche Bank head Christian Sewing said in Frankfurt recently.

"In reality, they advocate policies that run counter to the foundations of our success: openness, diversity, a strong Europe, reliable institutions and international cooperation," he added.

With polls suggesting that an absolute majority for the AfD cannot be ruled out, Sewing said he personally hoped "that this does not happen." From conversations with investors, he knew that many were deeply concerned about such an election outcome.

Munich economics professor Schnitzer, like Hüther, pointed out that many workers in Saxony-Anhalt would soon retire.

"Without an influx of people from outside the state, there will soon be a shortage of skilled workers. And without enough skilled workers, urgently needed investment will fail to materialize," Schnitzer said.