Von der Leyen seen dragging heels on Hungary and Poland

But shortly after that ruling, von der Leyen issued a statement indicating that she needed more time before moving ahead with the so-called conditionality mechanism, which went into force more than a year ago.

Even adopting guidelines on how to implement the law would take "weeks," said von der Leyen.

That was met with thinly disguised fury in the European Parliament, where a number of lawmakers saw the guidelines as delaying tactic.

A "smokescreen,'' said Finnish centre-right MEP Petri Sarvamaa, who had negotiated the law on behalf of the parliament.

A "fictional requirement invented by the commission," said Dutch liberal lawmaker Sophie in 't Veld in a tweet.

Even as lawmakers vented their frustration that the commission might delay action against the nationalist governments in Poland and Hungary after the court ruling, experts on EU affairs sounded a more cautious note.

John Morijn, a law and politics professor at the University of Groningen, said the commission really did need to build a rock-solid case — otherwise the mechanism could wind up becoming a dead letter, like previous attempts to tackle rule of law violations in Europe.

"The commission has one chance to do this right, it will be fatal if the commission's proposal is voted down in council," Morijn told EUobserver, referring to the body where EU governments have their say.

Such a vote would mean "the instrument is dead immediately," said Morijn.

And even if the commission launched the process right away, it still could take months before the council would likely take a final vote on imposing the sanctions, Morijn said.

That vote, which is the final stage of the procedure, operates by so-called qualified majority where any proposal by the commission to suspend funds to a member state would need the support of at least 15 out of 27 member states representing at least 65 percent of the total EU population.

There may also be political impediments that help explain von der Leyen's apparent lack of alacrity.

French president Emmanuel Macron, whose country currently holds the rotating EU presidency, may want to keep Budapest and Warsaw onside to win backing for his EU policies, while the new German government — while slightly tougher on rule of law issues than the previous government under Angela Merkel — still prefers dialogue, said Mujtaba Rahman, the director of the Eurasia Group consultancy.

There are also concerns in Brussels that triggering the regulation against Hungary would only serve to bolster the popularity of Hungarian prime minister Viktor Orbán ahead of the 3 April elections, Rahman said.

Even so, the commission was more likely, in the short term, to take action against Hungary than Poland, where parts of the governing coalition have sent positive signals about complying with EU court rulings and unblocking Covid-19 recovery funds, he said.

"The commission leans into Hungary and leans back from confrontation with Poland," Rahman said.

'Shame'

Many MEPs see the situation differently.

They are increasingly frustrated by a lack of action from the commission on rule of law issues. Last year MEPs voted to take the commission to court - and the parliament has started the procedure to do so.

Alongside their frustration over her reference to guidelines, MEPs also berated von der Leyen for missing a question and answer session with lawmakers at the parliament on Wednesday afternoon.

Her absence was a "shame," said Sarvamaa, the Finnish lawmaker.

Commission spokesperson Dana Spinant defended von der Leyen's decision to leave the parliamentary session early.

Von der Leyen was needed in Brussels for a meeting with "European partners in relation to the situation in Ukraine and Russia," Spinant told reporters.

Some MEPs have suggested that they could freeze the von der Leyen commission's funding, in the event that she doesn't now take swift action in rule of law cases.

"The parliament should examine the possibility of postponing the discharge for the commission's budget, so long as the commission does not trigger the rule of law mechanism," said German Green MEP Terry Reintke.