The move immediately drew criticism from some civil servants who saw it as a blow to freedom of speech at odds with the embattled government's Western-backed reform drive, Reuters wrote.
The rule on "loyalty" is one of several outlined in a new ethics code that civil servants must follow or face disciplinary action, according to a decree posted on the government website.
"The government has decided to introduce standards of ethical conduct for civil servants to restore public faith in the work of the state bodies and officials," the decree said.
Government employees should "avoid any public criticisms of the work of state institutions and their officials," the code stipulates, alongside rules on the need for transparency and integrity.
The shock resignations in February of Economy Minister Aivaras Abromavicius and a top prosecutor shone a spotlight on the failure of the Kyiv leadership to follow through on promises to eliminate the influence of vested interests on policymaking.
In a Facebook post about the new ethics code, Olena Minitch, a department head in the economy ministry, said the new rules appeared to have been "created hastily and adopted quickly" in the wake of Abromavicius's allegations about corrupt state practices.
"The little document ... is in the best traditions of the Communist period, more precisely in the traditions of Stalin and Beria," Minitch said, referring to repressive Soviet leader Josef Stalin and his security chief, Lavrenty Beria.
Others appeared to poke fun at the state's call for officials to toe the party line.
"I'm a loyal public servant. I'm thrilled with the work of state bodies (and) their officials," Ukraine's Ambassador-at-Large Dmytro Kuleba tweeted, linking to an article about the ban.
Не знаю - может совпадение, может случайность или действительно эти два события были связаны, но на следующий день, как ...
Опубликовано Lena Minitch 26 февраля 2016 г.
The future of the government itself is in doubt unless Prime Minister Arseny Yatsenyuk can shore up the coalition and avoid snap elections, having barely survived a no-confidence motion in parliament in February.
Yatsenyuk's approval ratings have plummeted to less than 1% since he came to office in 2014 after protests ousted the previous pro-Russian government. The economy has tanked and a conflict with separatist rebels has no end in sight.
The political turbulence has further delayed the disbursement of critical financial aid from the International Monetary Fund and raised doubts about Yatsenyuk's ability to win parliamentary support for promised reforms.
