LISBON - Portugal's newly elected Democratic Alliance (AD) minority government had its first clash on Tuesday with the far-right, accusing it of teaming up with the incumbent Socialists to block the appointment of the parliamentary speaker.

The AD coalition, helmed by the leader of the centre-right Social Democratic Party (PSD) Luis Montenegro, won the March 10 general election by a slim margin, far short of a working majority.

That result reflected a political tilt to right-wing populism and a weakening of Socialist governance across Europe, which is expected to result in gains for far-right parties in European elections in June.

In Portugal, analysts have anticipated instability for the AD minority government as, with just 80 seats in the 230-seat legislature, it might become dependent on far-right party Chega, which quadrupled its parliamentary representation to 50 lawmakers, to pass legislation.

Montenegro has repeatedly refused any government agreement with Chega, something Chega party leader Andre Ventura has demanded to allow the AD to pass legislation in parliament.

In a surprise move on Monday, Ventura announced his party had reached an agreement with the AD to allow PSD lawmaker Jose Pedro Aguiar Branco to be elected parliamentary speaker.

However, after a vote on Tuesday during the parliament's first session after the election, Aguiar Branco, initially the sole candidate to the role, was rejected as he only received 89 votes in favour, not reaching the required majority of 116, meaning that Chega's lawmakers did not comply with the agreement.

After Aguiar Branco failed to get enough votes, the PS and Chega proposed their own candidates - Francisco Assis and Manuela Tender, respectively - and the parliament held a second round of voting to choose between the three.

None of the candidates received sufficient ballots to be nominated and lawmakers had to vote a third time but again failed to elect a parliamentary speaker. The process restarts at 1200 GMT on Wednesday.

"We saw the first negative coalition between the Socialist Party (PS) and Chega," said Joaquim Miranda Sarmento, leader of the PSD's parliamentary bench.

PS' parliamentary bench leader, Eurico Brilhante Dias, described Sarmento's accusation as bad faith because his party was not consulted by the AD, which opted to make an agreement with Chega.

"The agreement between the (two) right-wing parties did not work," Brilhante Dias said. "It was torn out in less than 24 hours."

Ventura, denying he had instructed his lawmakers to make Aguiar Branco's appointment unfeasible, accused several AD leaders of repudiating the existence of an agreement.

"The AD has to choose who it wants to ally with," Ventura said.

Political scientist Marina Costa Lobo previously told Reuters it was "difficult to predict Chega's behaviour because they're an anti-system party". REUTERS