Belgian Prime Minister Charles Michel leaves a polling booth to cast his vote for the European elections in Limal on May 26, 2019 | Eric Lalmand/AFP via Getty Images Belgian government deadlock muddles EU commissioner appointment The country is used to long negotiating periods, but forming a coalition could be especially tricky this time.

Expected difficulties in forming a new Belgian government are casting doubt over who will appoint the country's next European commissioner.

The country is used to long negotiating periods — its record is 589 days without a government — but patching together a majority coalition at the national level could be especially tricky this time.

Belgium held a “triple election” on Sunday for the federal, regional and European parliaments, in which the northern region of Flanders voted to the right and the southern Wallonia region to the left. Any coalition would likely be dominated by one of the regional majorities and therefore lack a (not required but politically sensitive) majority in the other region.

But Belgium has a decision to make: following European elections, every member country's government is expected to put forward a European Commission candidate by September.

"If Belgium has no new government by then, that will be a decision for the caretaker government," said Stefan Sottiaux, a professor in constitutional law at Leuven University.

Belgian Prime Minister Charles Michel has led a caretaker government since resigning in December following the exit of the nationalist New Flemish Alliance from the coalition.

According to Sottiaux, the appointment may even need parliamentary approval as Michel's government no longer holds a majority.

But a spokesperson for Michel told POLITICO that "the commissioner appointment is part of the negotiations for the Belgian government."

The unwritten rule is that when Belgian coalition partners divide up the government top jobs after an election, the European commissioner is treated like a Cabinet post. It is given a value of three points, the same as the prime minister. Deputy prime ministers are worth two points, and ordinary ministers one point.

"The parties of the outgoing government will try to make their pick from the parties that are likely to end up in the next government," former Belgian Deputy Prime Minister Johan Vande Lanotte said.

A sitting government has a greater chance of lobbying for a good EU portfolio, he added.