A deal that would have had Yemen President Ali Abdullah Saleh leave office within thirty days fell through over the weekend, as he refused to sign the deal brokered by fellow Gulf states. The formal signing ceremony was supposed to happen today.

Saturday’s development was a new blow to efforts to mediate the months-old crisis between Ali Abdullah Saleh and demonstrators inspired by protests sweeping through the Arab region to demand his overthrow.

Abdul-Latif al-Zayyani, secretary-general of the Gulf Co-operation Council (GCC), which brokered the agreement, had flown to the Yemeni capital, Sanaa, on Saturday to urge Saleh to sign the deal.

Instead, he met high-level leaders of Saleh’s governing political party and parliamentary bloc, where he was informed that Saleh had some reservations over the deal.

Members of Saleh’s ruling party said he was willing to sign the deal as the head of his political party but not as President. Analysts believe this is just a stalling tactic, an attempt by Saleh to hold power.

The Yemeni opposition had agreed to the deal, while the protest movement in the streets thundered against it, because it afforded Saleh legal immunity and because they didn’t trust Saleh to actually step down. There has been no let-up in street protests since the deal was announced, nor has there been an end to violent repression, with multiple deaths across the country yesterday. At least 150 protesters have died at the hands of security forces since the beginning of the uprising three months ago.

The political opposition, incensed by agreeing to the transfer of power only to see Saleh back out of it, said they would increase pressure on the President, perhaps through returning to the streets with the protesters.

Saleh would be the third dictator to be deposed in the Arab spring. The other two, Hosni Mubarak in Egypt and Zine El Abidine Ben Ali in Tunisia, did not get legal immunity as part of a deal for stepping down. Mubarak is under detention in Egypt and Ben Ali is in exile in Saudi Arabia, with international warrants out for his arrest.

The Saudis brokered this deal after losing confidence in Saleh and fearing instability in the Gulf. Their reaction to this defiance will be crucial going forward. The United States has generally followed the Saudis during the Arab uprising. US officials are also concerned about increased Al Qaeda activity during the uprising, as their counter-terrorism efforts in Yemen have basically been shut down.