BEIRUT, (Reuters) – Lebanese Prime Minister Fouad Siniora accused the pro-Syrian Hezbollah party of plotting a coup against him on Friday, escalating the war of words between the Western-backed government and opposition forces.

Hezbollah chief Sayyed Hassan Nasrallah told thousands of supporters on Thursday that he would not yield in his battle to oust Siniora and said some government officials had tried to sabotage the guerrilla group in this year’s war with Israel.

Siniora hit back in a televised speech, rejecting the accusations and accusing the Shi’ite Hezbollah of trying to intimidate its opponents into submission. “You are not our God and the party (Hezbollah) is not our God … Who appointed you to say ‘I am right and everything else is wrong?'” said Siniora, who is a Sunni Muslim.

Opposition parties, which include a populist Christian group, have occupied two squares in central Beirut for more than a week and have vowed not to budge until Siniora yields to their demands for a government of national unity.

Some political analysts say the stand-off could spark sectarian strife in a country that has fought two civil wars in the past 50 years and is struggling to recover from the 34-day war against Israel in July and August.

A fiery Nasrallah said on Thursday Siniora had tried to get the Lebanese army to cut supply routes to his guerrillas during its battle with Israeli forces — an inflammatory accusation which both the government and army have denied.

Nasrallah has called for a mass rally on Sunday and said on Thursday if Siniora’s allies did not yield soon he would ratchet up the pressure yet further and push for early elections.

The prime minister told a room full of supporters that Nasrallah was “trying to launch a coup d’etat, or at least threatening us with a coup d’etat and defining its outcome in advance. This does not lead to results.”

In a show of Muslim unity, a Lebanese Sunni preacher led thousands of Shi’ite protesters in prayers on Friday, saying the on-going crisis was purely political. “This mass protest is not for Shi’ites or for Sunnis or any other sect. It is for all of Lebanon,” said Preacher Fathi Yakan, who leads a small Sunni group which backs the opposition.

But underscoring the sectarian undercurrents at play in Lebanon, the country’s top Sunni cleric said his community would not allow the government to give in to the crippling protests. “We consider … toppling Prime Minister Fouad Siniora and his government in the street is a red line. It is a red line that we will not allow to be crossed,” Grand Mufti Mohammed Rashid Qabbani said after Friday prayers.

Siniora and most of his ministers are holed up in government headquarters, fearing for their lives after the assassination last month of Industry Minister Pierre Gemayel. If two more ministers resign or die, the government will automatically fall.

Shi’ite parties withdrew their ministers from the cabinet in November and have demanded that the opposition be given the right of veto in any new administration.

Siniora’s allies say their opponents are looking to derail plans to set up an international tribunal to try suspects in the 2005 assassination of former Prime Minister Rafik al-Hariri, which many Lebanese blame on Syria, a charge Damascus denies.

Sunni leaders in Egypt, Saudi Arabia and Jordan have thrown their weight behind Siniora, alarmed by the growing influence of Shi’ite Iran, which funds Hezbollah.

Egyptian President Hosni Mubarak told French television on Friday that the opposition was not being “reasonable”. “There is also the risk of outside interference in these demonstrations. That can lead to very serious confrontations and even lead to the destruction of Lebanon,” he said.