Rival lawmakers struggled for control of Kosovo's parliament on Thursday, as it sat for the first time since an inconclusive June election triggered a constitutional crisis unprecedented in the young state's short history.

An opposition bloc, supported by deputies representing some of Kosovo's ethnic minorities, elected the leader of the largest opposition party as speaker of parliament, but only after lawmakers from the party of outgoing Prime Minister Hashim Thaci declared the session adjourned and walked out.

The chaotic scene spoke to a deepening crisis over who will rule the impoverished country of 1.7 million people for the next four years.

Thaci's Democratic Party of Kosovo (PDK) emerged from the election as the biggest party, with 30 percent of votes. But three opposition parties have united in a bid to outmanoeuvre the PDK and thwart Thaci's bid for a third consecutive term as prime minister.

The election as speaker of Isa Mustafa, leader of the Democratic League of Kosovo (LDK), suggested the party may have the makings of a working majority.

In an urgent meeting the PDK said it would not recognise the voting and would take the case to the constitutional court.

“The losing political parties … today have violated the highest institution,” PDK said in a statement.

“PDK considers invalid all the decisions taken from the occupiers of today’s session and will not recognise these decisions that came from an illegal, anti-democratic and anti-constitutional process.”

The opposition bloc has so far failed to bring on board a fourth party - Vetevendosje (Self-Determination) - and it was unclear on Thursday whether the alliance would settle instead for the support of the ethnic minorities.

They accuses Thaci's administration of corruption, nepotism and failure to press economic reforms - accusations he denies.

All parties seek a closer integration with the European Union, but some, notably Vetevendosje, take a harder line on negotiations with Serbia that are crucial to both countries' hopes of one day joining the bloc.

Vetevendosje has also called for a halt to the sale of big state enterprises as a condition of joining the government.

The opposition says their candidate for prime minister is Ramush Haradinaj, a former guerrilla commander twice indicted and twice cleared of war crimes by the United Nations war crimes tribunal in The Hague.

Kosovo's president should in the next few days nominate a candidate for prime minister who would then have 15 days to name a cabinet and win its approval by parliament.

It remains unclear when the parliament will proceed with voting on a new government.

Kosovo declared independence from Serbia in 2008, almost a decade after NATO air strikes drove out Serbian forces accused of expelling and killing ethnic Albanian civilians in a two-year counter-insurgency war.