Alexander De Croo resigned after his Open Flemish Liberals and Democrats party slumped in Belgium elections.

Belgium’s Prime Minister Alexander De Croo speaks to the press as he arrives to attend a European Council summit at European Union headquarters in Brussels [John Thys/AFP]

Belgium has kicked off its quest for a new governing coalition after elections pushed centre-right parties into prime positions across the country, in a rare alignment.

Sunday’s regional and national vote saw the conservative New Flemish Alliance (N-VA) maintain its decade of control in Dutch-speaking Flanders, beating far-right Vlaams Belang, in second place.

Meanwhile in French-speaking Wallonia, the centre-right Reformist Movement smashed through the long-standing supremacy of the Socialist Party. They also claimed first place in Brussels.

On Monday, Prime Minister Alexander De Croo – who had seen his Open Flemish Liberals and Democrats party haemorrhage support – handed in his resignation to King Philippe as per protocol.

“This is an extremely hard evening for us. We have lost this election,” De Croo said, adding he would take full responsibility for the loss.

N-VA chief Bart De Wever, the current mayor of Antwerp, could be the most likely PM candidate to get the initial nod – as his party claimed the most seats (24) in the 150-seat federal parliament.

“We’re completely moving away from the traditional Belgian narrative of the last 50 years, according to which Flanders is on the right and Wallonia is on the left,” Vincent Laborderie, a professor at UCLouvain university, told AFP news agency.

“We have the impression of a structural shift in the electorate towards the centre right.”

Over the coming months, political parties in Belgium will seek to forge a governing coalition between the largely right-of-centre parties of the Dutch-speaking north, and the more left-leaning parties of the French-speaking south.

With its complex regional and national system, Belgium has an unenviable record of painfully protracted coalition discussions – reaching 541 days back in 2010-2011.

“Logically, we should go faster this time,” Laborderie said, still suggesting that it would take six months to find a “landing”.

In the meantime, De Croo will remain caretaker prime minister.