BUCHAREST (Reuters) - Romania’s outgoing parliament has been one of the most inefficient since the fall of communism, plagued by corruption investigations and weak activity, a Romanian think-tank said on Monday.

Rated one of the European Union’s most corrupt states, Romania holds a parliamentary election on Dec. 11 but 89 of the 588 lawmakers elected in 2012, or 15 percent, have not completed their terms, the Institute for Public Policy (IPP) said.

Most of those 89 are either under investigation for graft or have already been convicted, or else quit early to participate in local elections or to take up other positions.

Romania’s justice system is subject to special monitoring by the EU, though the country’s anti-corruption prosecutors have won praise for a series of crackdowns on graft targeting ministers, lawmakers, mayors, magistrates and businessmen.

The IPP study said Romanian lawmakers had filed 1,689 legislative initiatives in the 2012-2016 period but only 14 percent of them became laws, while the government filed 870 draft laws, of which more than 80 percent were approved.

Another striking feature of this parliament has been movement between political parties, with 223 lawmakers no longer belonging to the party for which they were originally elected, the IPP study showed.

Romania has been led by a government of technocrats since November 2015, when massive street protests in the wake of a deadly nightclub fire prompted the leftist cabinet to step down.

The leftist Social Democrats (PSD) are likely to win this month’s election, returning to power after a year-long gap, an opinion poll showed on Saturday.