Wolfgang Kubicki, the deputy chairman of the opposition Free Democrats (FDP), said Richard Grenell’s repeated interference in German sovereignty should prompt Foreign Minister Heiko Maas to immediately declare Grenell persona non grata.

“Any US diplomat who acts like a high commissioner of an occupying power must learn that our tolerance also knows its limits,” said Kubicki, who is also one of five deputy speakers of Germany’s Bundestag parliament.

Grenell had on Tuesday criticized Germany’s military spending plans within NATO as insufficient, prompting Kubicki to accuse the envoy of “interfering” repeatedly in political issues of a sovereign country.