Opposition lawmakers in Kosovo fired tear gas and pepper spray in parliament on Tuesday, the latest such incident in a deepening political crisis over relations with former master Serbia.

The protest was led by prominent opposition figure Albin Kurti, who has set off tear gas in the chamber several times to demand the government scrap a deal to regulate ties between Serbia and its former southern province.

Lawmakers, who were due to debate the government's proposed budget for next year, left the chamber, but appeared to be trying to hold the session in another room.

Kurti fired pepper spray at police.

An alliance of opposition parties, led by Kurti's Self-Determination party, opposes a European Union-brokered deal to grant minority Serbs in majority-Albanian Kosovo greater local powers and the right to some financial links with Belgrade, creating a so-called "association" of Serb municipalities.

"I pointed the pepper spray at the prime minister and the government because they created the 'association'," Kurti told Reuters in the assembly.

"The police just happened to be in the wrong place."

Kosovo broke away from Serbia in 1999, when NATO bombed for 11 weeks to stop the killing and expulsion of ethnic Albanians by Serbian forces trying to crush a guerrilla insurgency.

The territory of 1.8 million people declared independence in 2008 and has been recognised by over 100 countries, including the major Western powers.