BUCHAREST (Reuters) - Romania’s ruling Social Democrats and thousands of supporters rallied outside government headquarters in Bucharest on Saturday in protest at alleged abuses of power by anti-corruption prosecutors.

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The rally was seen as the ruling coalition’s response to a series of large anti-government street protests held against Social Democrat attempts to decriminalize several corruption offences via emergency decree last year. The popular outcry forced the Social Democrats to withdraw the decree.

Romania is one of the European Union’s most corrupt states and Brussels keeps its justice system under special monitoring.

The argument over how hard to fight corruption in Romania has dominated its politics since it joined the EU in 2007.

Anti-corruption prosecutors have secured a spate of convictions against lawmakers, ministers and mayors in recent years, exposing conflicts of interest, abuse of power, fraud and the awarding of state contracts in exchange for bribes.

But leading politicians, some of whom are currently under investigation or on trial, have denied wrongdoing and accused prosecutors of using their powers for political persecution.

They have also accused them of relying too much on tip-offs from third parties to build cases.

“You mustn’t be under the illusion that only high-ranking officials or public servants are targets,” Social Democratic party leader Liviu Dragnea told thousands of supporters clad in white T-shirts and waving flags.

Local television stations have estimated just under 200,000 people were gathered, although riot police did not offer official figures. Dragnea dove into the crowd to strains from Beethoven’s Ode to Joy, which is also the EU anthem.

“Nobody is safe. Absolutely everyone can be targeted by a tip-off which could lead to a conviction,” Dragnea said.

Dragnea himself was convicted in a vote-rigging case, barring him from the post of prime minister. He is now on trial in a separate case for allegedly instigating abuses of office by other public servants, and is under investigation on suspicion of pocketing EU funds. He denies wrongdoing in all three cases.

Social Democrat lawmakers are currently trying to revise the criminal code and critics have said some of the proposed changes would damage investigations.