Lawmakers in the Czech Republic have entrusted oversight of the police force to a former member of a communist-era special unit that tried to crush the peaceful 1989 uprising that helped bring down communist rule.

The unprecedented appointment of Zdenĕk Ondrácĕk as chair of parliament’s general inspection of security forces commission appeared to be part of complex manoeuvring by billionaire businessman Andrej Babiš and his ANO party to get backing for a minority government.

The ANO has 78 seats in the new 200-seat lower house. Babiš, the new prime minister, is seeking support – or at least acquiescence – from lawmakers of the other eight parties in parliament.

The far-left Communist party, with 15 seats, and far-right anti-EU SPD party, with 22 seats, have lent support in initial parliamentary votes in return for committee posts, but no deal has been announced on their backing for an ANO cabinet.

The secret ballot on Tuesday to appoint Ondrácĕk was the first time the Communist party had gained such a post in the nearly three decades since the fall of communism.

In 1989, Ondrácĕk’s police unit used water cannon, clubs and dogs to disperse anti-regime protesters. The demonstrations eventually led to the peaceful overthrow of communist dictatorship in what became known as the velvet revolution.

Some political leaders criticised his appointment. “It is sad that it happened only one day after we remembered the anniversary of (late president and leading anti-communist dissident) Václav Havel’s passing. The times have changed,” said the deputy chair of the Mayors and Independents party, Vít Rakušan.

The Communist party deputy chairman, Jiří Dolejš, defended the appointment. “Police work should be scrutinised by those who understand it,” he told reporters.

The party, which suffered the worst election result in its near 100-year history in October, is so far the only faction to say it could back the ANO government.

Direct or indirect support could also come from the SPD party founded by Tomio Okamura, a Czech-Japanese businessman.

Other parties have shunned Babiš, mainly due to pending police charges against him amid allegations he concealed his company’s ownership of a farm and conference centre a decade ago to illegally obtain a €2m EU subsidy. He denies wrongdoing.

Babiš, who was appointed prime minister this month and whose cabinet took power last week, has until mid-January to win a confidence vote.

The Czech president, Miloš Zeman, has said Babiš will get a second try if his first attempt to form a government fails.

