WARSAW (Reuters) - The leader of Poland’s anti-government protest movement acknowledged on Thursday taking money from the organization, dealing a blow to the parliamentary opposition, but he said the funds were for contract work he had carried out.

The ruling conservative Law and Justice (PiS) party urged the opposition to cut ties with Mateusz Kijowski, leader of the Committee for the Defence of Democracy (KOD). Opposition members also demanded a swift explanation.

Polish daily Rzeczpospolita and the news portal Onet.pl reported that Kijowski had channeled more than 90,000 zlotys ($22,000) from donations to KOD to his private account.

The news came in the third week of a sit-in protest in parliament by opposition lawmakers who on Dec. 15 blocked the plenary hall podium over proposals by PiS to curb media access to parliament.

After the December political standoff, Poland’s largest in recent years, the European Union, concerned about what it called a continued “systemic threat to the rule of law”, gave Warsaw two months to resolve the crisis.

Kijowski, who has organized dozens of protests over the past year against the government, said the funds were transferred for earlier agreed contract work for KOD.

“The case is highly unfortunate,” Kijowski told reporters.

PiS used the situation to call on the opposition to disassociate itself from Kijowski, while some opposition leaders called for a quick and transparent explanation.

“I hope that Mateusz Kijowski ... will in an open, transparent manner answer questions and explain those difficult...issues,” Grzegorz Schetyna, the leader of Poland’s largest opposition group, the Civil Platform (PO), told journalists.

Lawmakers, many of whom are close to Kijowski, have been taking turns to sit in parliament during its holiday recess, vowing to continue the protest until PiS repeats its vote on the 2017 budget, which on Dec. 15 had to take place in an auxiliary chamber because of the blockade in the main hall.

The lower house of parliament returns to session on Jan. 11.