Polish Prime Minister Donald Tusk on Friday warned nationalist vigilantes patrolling the German border to stand down, calling their actions illegal and disruptive, as his government grapples with rising tensions both on the frontier and within his ruling coalition.

The warning follows Warsaw’s decision to temporarily reinstate border checks with Germany and Lithuania starting July 7, citing an unsubstantiated spike in migrants being pushed back by German authorities.

In recent days, self‑declared “citizen patrols,” some reported to number in the hundreds, have gathered on the Polish side of the German border, claiming to prevent migrant returns sent by Berlin.

The fracas over these patrols has strong political implications, and could pile pressure on Tusk’s increasingly fragile centrist coalition. While the government is telling the vigilantes to go home, conservative nationalist President-elect Karol Nawrocki is praising them.

“Only the Border Guard has the right to control our borders,” government spokesperson Adam Szłapka said after a hastily convened security meeting in Warsaw. “Anyone impersonating officers or hindering their work will face consequences.”

Videos circulating online show masked men stopping cars, asking for identification and attempting so-called “citizen arrests” of those they suspect of illegal entry. Regional officials have warned the actions may constitute impersonation of public authority and pose risks to public safety.

Tusk branded the groups’ political backers, including some opposition lawmakers, “shameful and scandalous.”

Nawrocki, by contrast, thanked one of the organizers, far-right activist Robert Bąkiewicz, earlier this week for what he called a “citizen-led defense of the border” — a comment critics argue risks legitimizing the self-appointed patrols.

The decision to close the border was meant to give Tusk a platform to project strength at a precarious moment for his government.

The premier is under pressure to reassert control following a humiliating defeat in last month’s presidential election, when Tusk–backed Rafał Trzaskowski lost to Law and Justice (PiS)-supported Nawrocki. The loss has shaken the alliance that brought Tusk to power in 2023 and emboldened his coalition partners to explore their options.

In a sign of growing friction, junior coalition partners, including parliamentary Speaker Szymon Hołownia, were seen Thursday meeting privately with PiS lawmaker Adam Bielan, and reportedly even PiS leader Jarosław Kaczyński, in a late-night gathering that has fueled speculation of behind-the-scenes maneuvering.

Tusk’s team insists the prime minister remains firmly in charge. He is expected to carry out a cabinet reshuffle later this month, a move seen in Warsaw as a test of his ability to reassert authority within the fractious coalition.