The small opposition party wants Grenell, 52, to be declared persona non grata for having “actively interfered” in German politics on issues from Iran to defence spending and telecom equipment.

Although the motion, a copy of which was seen by AFP, has little chance of  succeeding, the fact it has been made at all is a sign of the badly strained transatlantic relations in the Trump era.

The US president has harshly criticised NATO ally Germany and its Chancellor Angela Merkel on issues ranging from immigration policy to defence spending and car exports.

SEE ALSO: 'Top diplomatic failure': U.S. Ambassador sparks anger in Germany 

Last week Wolfgang Kubicki of the opposition liberal Free Democrats also demanded that Grenell be sent home for “behaving like the high commissioner of an occupying power”.

For almost a year, Grenell, a hawkish supporter of Trump's “America First” stance, has weighed in on German politics with tweets, regularly angering his host country.

Grenell made a splash on day one in his diplomatic post by tweeting that German companies should get out of Iran after Trump ripped up the nuclear deal with Tehran.

He soon followed up with reported comments to right-wing news website Breitbart of his ambition to “empower other conservatives throughout Europe, other leaders.”

At the time, Social Democratic lawmaker Thorsten Schaefer-Guembel tweeted that “European citizens don't need a Trump vassal to tell them who to vote for”.

Grenell has also criticised Germany for spending too little on defence, attacked plans for a new gas pipeline from Russia and warned Berlin not to use telecom equipment made by China's Huawei.

SEE ALSO: What you should know about Trump's new ambassador to Germany