BERLIN/FRANKFURT (Reuters) - German lawmakers on Monday criticized deputy finance minister Joerg Kukies and Goldman Sachs, alleging a conflict of interest in the U.S. investment bank advising state-backed Commerzbank on a possible merger with Deutsche Bank.

FILE PHOTO: Outside view of the Deutsche Bank and the Commerzbank headquarters in Frankfurt, Germany, March 18, 2019. REUTERS/Ralph Orlowski

Kukies, who was formerly co-head of Goldman Sachs GS.N in Germany, left the Wall Street firm a year ago to become deputy German finance minister.

Kukies has since advocated a merger between Commerzbank CBKG.DE and Deutsche Bank DBKGn.DE, which unions warn could mean up to 30,000 job cuts, people familiar with the matter say.

Goldman Sachs is advising Commerzbank on the $28 billion plus deal deliberations, people familiar with the matter said.

“It’s a conflict of interest,” Fabio De Masi, a prominent leftist lawmaker in the German parliament, said, pointing to the state’s 15 percent stake in Commerzbank.

A spokesman for Kukies told Reuters there was no conflict of interest and that he had worked in the trading department at Goldman Sachs, which was “strictly separated” from bankers who advised on mergers.

Goldman Sachs declined to comment.

“In his 17 years at Goldman Sachs, Joerg Kukies exclusively worked for the sales and trading sector with no responsibility for the advisory/mergers and acquisitions section,” the spokesman for Kukies said.

Although confirmation of merger talks between Germany’s two largest banks, following months of speculation, has boosted their share prices, it has also triggered opposition and concerns over the impact on employment.

The issue is a highly emotive one in Germany and in its Tuesday edition, top-selling tabloid newspaper Bild raised a question mark over Kukie’s future in the government.

“When 30,000 jobs are on the line, the government must avoid the impression of a conflict of interest,” De Masi added.

This was echoed by Danyal Bayaz, a German parliamentarian and finance expert from the country’s Green party.

“In the financial crisis, we saw that government and finance were too interconnected. Ten years later, we don’t want to have the same. We want a strict separation from politics and industry,” Bayaz said.

“It is important to avoid the appearance of conflict of interest,” he added.