Prime Minister Viktor Orban of Hungary seems to have a predilection for periodic antics that leave his neighbors in the European Union slack-jawed -- and nervous.

His latest -- and most serious -- attention-getting stunt took the form of a vote in the Parliament this week that essentially does away with the separation of powers, a basic building block of democratic governance. Orban's nationalist Fidesz party, which holds a two-thirds majority in the legislature, pushed through changes to the constitution that chip away at fundamental checks and balances and further consolidate the prime minister's power.

These include a staggeringly cynical provision that removes the Constitutional Court's authority to fulfill its basic mission, that of determining whether constitutional amendments are, in fact, constitutional. The amendment gives the high court a say only on whether appropriate procedure has been followed in adopting a law, but not on its content. It also potentially erases about 20 years of the court's jurisprudence on human rights and other issues that predate the new Constitution that took effect Jan. 1, 2012.

Other measures that are only slightly less alarming include a ban on political advertising on any media other than state-owned broadcasters and the criminalization of homelessness.

The moves are consistent with Orban's increasingly bold machinations to obtain control of Hungary's political and economic institutions. Earlier this month, the prime minister raised concerns by naming a close ally, the former economics minister Gyorgy Matolcsy, to replace the Central Bank governor, who had demonstrated an independent streak by resisting the government's attempts to influence monetary policy.

Orban has also rattled markets by suggesting that he might limit the presence of foreign banks and could push to convert foreign-currency loans into loans denominated in forint. This week, the currency plunged to its weakest level in more than nine months as investors speculated that the government's proposals could be intended to depreciate the forint as a way to increase exports.

The U.S. has warned that Hungary's amendments could damage essential democratic safeguards. The European Union, of which Hungary is a member, has also had harsh words. Immediately after the vote, European Commission President Jose Manuel Barroso and Thorbjorn Jagland, the secretary-general of the Council of Europe, the human-rights watchdog, said the changes raised "concerns with respect to the principle of the rule of law, EU law, and Council of Europe standards." German Foreign Minister Guido Westerwelle reminded Hungary's president that Europe is "a community built on values" and that Europe expects "these values to be upheld."

For all the tough talk, though, there isn't a lot the EU can do. Any formal sanction or punishment involves either a long and complicated legal process or the approval of all of the EU's 27 members, which has proved largely fruitless in past cases. European leaders, including Westerwelle and Barroso themselves, have made clear they are acutely aware of this shortcoming and have called on the EU to come up with new tools that can be deployed swiftly and effectively when a member state steps over the line.

The need is particularly urgent now, as Europe's leaders struggle to counter the weariness and skepticism that have taken hold across the continent in the wake of the debt crisis. Their calls for a tighter union will be a hard sell if they prove unable to hold repeat offenders such as Hungary to minimal standards of democracy.

(Max Berley is a member of the Bloomberg View editorial board. Follow him on Twitter.)