BUDAPEST — Prime Minister Viktor Orban of Hungary tightened his grip on power on Wednesday, as the Hungarian Parliament, controlled by Mr. Orban’s far-right party, approved the creation of a parallel court system that cements executive control over the judiciary.

Once the new system begins operating within the next 12 months, Mr. Orban’s justice minister will control the hiring and promotion of its judges, who will have jurisdiction over cases relating to “public administration” — including politically sensitive matters like electoral law, corruption and the right to protest.

Hungary’s existing judiciary, which already faces significant meddling by Mr. Orban’s government, will continue to work — but with a reduced mandate, and with no oversight of the parallel court system, known as the administrative courts.

Civil rights watchdogs see the move as the latest erosion of democratic institutions under Mr. Orban, who since entering office in 2010 has created a blueprint for backsliding from the liberal democracy that took hold in Eastern Europe in the 1990s. His example has been followed in democracies like Poland, and has won admirers among a generation of populist figures in France, Italy, the Netherlands and the United States.