Hezbollah leader Sayyed Hassan Nasrallah said on Thursday his party was not happy with the prime minister's helping to fund a U.N.-backed court investigating the killing of statesman Rafik al-Hariri, but that it would not work against it.

Lebanon, facing international pressure, has now paid its more than $30 million (19 million pounds)share resolving months of political wrangling that threatened to bring down the government.

Prime Minister Najib Mikati had threatened to resign if he could not fund the Special Tribunal for Lebanon, which is investigating the 2005 bombing that killed former Prime Minister Rafik al-Hariri and has indicted four Hezbollah members.

Hezbollah, a powerful Shi'ite political party and guerrilla group, backed by Iran and Syria, rejects what it labels as a politicised and conspiratorial court as biased in U.S. and Israeli interests.

But he said in his televised speech commemorating the Shi'ite Muslim holiday of Ashoura that his party would not do anything to jeopardise stability in Lebanon.

We stress our firm rejection of the legality and constitutionality of funding the court or cooperating with it in any way, but we will not cause a problem in the country and we will serve the higher national interest, he said.

Nasrallah said Mikati had embarrassed himself by moving to fund the international investigation.

Mikati came to power in January with Hezbollah's support when the last government fell over disputes about the court. Hezbollah and its allies have the power block measures in cabinet with half the seats, but Nasrallah softened his tone over the funding issue to avoid a public clash.

He stressed the funding in no way reflected his party's indirect acceptance of the court, and said there was no intention to hand over the four Hezbollah suspects: The one has nothing to do with the other.

(Reporting by Erika Solomon and Laila Bassam; Editing by Jon Hemming)