Slaughter set to continue as Assad backs away from ceasefire plan

President in 11th-hour request for written guarantees from rebels as death toll soars

Hopes for a Syrian ceasefire faded dramatically yesterday as rebels rejected a last-minute demand from the regime for "written guarantees" that they will lay down their arms after government troops withdraw.

The 11th-hour request from President Bashar al-Assad was widely dismissed by opposition members and analysts as another stalling technique. It came as the joint UN-Arab League envoy, Kofi Annan, hit out at what he termed an "unacceptable" escalation in violence that violated promises made to him by Syria.

At least 40 more people were reported to have been killed by yesterday afternoon, after one of the bloodiest days of the uprising on Saturday, when 127 people died in crushing assaults across the country, according to the Local Coordination Committees.

"I am shocked by recent reports of a surge in violence and atrocities in several towns and villages in Syria, resulting in alarming levels of casualties, refugees and displaced persons, in violation of assurances given to me," Mr Annan said.

The ceasefire, part of a six-point plan put forward by Mr Annan and accepted by the Syrian government earlier this month, requires President Assad to begin his withdrawal of troops and tanks by tomorrow, before a truce from both sides within 48 hours.

However, the Syrian foreign ministry spokesman, Jihad Makdissi, said yesterday that Mr Annan's "interpretation" that the government had confirmed it will pull back troops is incorrect. "[Mr Annan] has not delivered until now written guarantees regarding the approval of terrorist armed groups to end violence and readiness to lay down their weapons," he said. He added that Syria also wanted assurances from Qatar, Saudi Arabia and Turkey that they would cease funding the opposition.

Colonel Riad al-Asaad, commander of the Free Syrian Army (FSA), said that his organisation of rebel militias did not recognise President Assad and therefore would not supply it with any written guarantees, which he said he had not been asked for. He said that if the regime stood by its promise to withdraw, the FSA would abide by the ceasefire, but he believed the plan was doomed. "The regime will not implement this plan. This plan will fail," he said from Turkey.

Failure to comply with tomorrow's deadline could provide the trigger for tougher action by the international community. The Turkish Prime Minister, Recep Tayyip Erdogan, whose country is swamped by an influx of refugees, said yesterday that he would "implement steps" if the ceasefire was ignored, the Hurriyet newspaper reported. A humanitarian corridor for refugees is one of the proposals that has been floated.

Analysts and members of the Syrian opposition have been sceptical of President Assad's commitment to the peace plan from the outset. "Assad has been using Kofi Annan's plan as a tool to give him time to carry on killing," said Chatham House Syria expert Rime Allaf.

"With the unbelievable death toll in the past few days the Syrian opposition has once again been proven right in saying this is a regime that will never abide by its word. It's typical that at the last minute, just days before the ceasefire deadline, they put forward a ridiculous request for written guarantees from the opposition."

Yesterday's demand came after the US embassy in Damascus warned that close monitoring of the situation by satellite meant that the Syrian government would not be able to fool the international community over its promise to remove heavy weapons and troops.

"The regime and the Syrian people should know that we are watching," said the US ambassador, Robert Ford. "The regime cannot hide the truth."

The embassy released images which showed some limited pull-back in the town of Da'el in the southern province of Deraa and Taftanaz in Idlib province. However, the pictures confirmed that heavy artillery remains in Idlib city.

Timeline: path to the ceasefire that never was

18 August 2011: After five months of relentless attacks by the regime of President Assad, right, on opposition forces, the US, Britain, France, Germany and the European Union demand Assad resign, saying he is unfit to lead.

4 October 2011: Russia and China veto a European-backed UN resolution that threatened sanctions against Syria if it didn't immediately halt its military crackdown on civilians.

29 December 2011: President Assad allows a team of Arab League observers to monitor his regime's compliance with a new plan to end the violence. After a month, observer mission is halted due to escalating violence.

4 February 2012: Russia and China veto another UN resolution that backed an Arab League plan calling on Assad to step down.

23 February 2012: The former UN Secretary General Kofi Annan, right, is appointed special envoy to Syria.

10 March 2012: Mr Annan travels to Syria and meets President Assad. He leaves a few days later, and proposes a six-point peace plan which would include ending the movement of troops into Syrian towns, a withdrawal of heavy weapons and the start of a more general troop pullout from troubled areas.

2 April 2012: Mr Annan tells the UN Security Council the Syrian government has agreed to a 10 April deadline to implement the first stages of his ceasefire plan.

8 April 2012: Amid international scepticism that Assad is committed to ending the violence and after some of the deadliest assaults yet on opposition fighters, the Syrian regime puts new conditions on the ceasefire, including that rebel fighters agree in writing to lay down their weapons – conditions rejected by the opposition.