A truce was said to be in the bag on Tuesday night, but hit stumbling blocks in a sign of the problems that lie ahead

As frantic diplomatic efforts continued to secure a ceasefire in Gaza between Israel and Hamas, which saw the US secretary of state, Hilary Clinton, arrive in Cairo on Wednesday vowing to work to find an end to the latest conflict, details of the stumbling blocks in the negotiations began to emerge.

On Tuesday evening, despite the continuing violence, an imminent ceasefire appeared certain to many close to the negotiations.

One diplomat who attended an event in Cairo with a number of prominent Islamist politicians was assured a truce "was in the bag" and went to sleep expecting to wake to news of a ceasefire.

But what happened in the period between when Egypt's president, Mohamed Morsi, and a senior Hamas spokesman indicated a truce would be in force by Tuesday night is instructive of the profound problems that lie ahead in attempting to secure a meaningful long-term ceasefire.

According to those familiar with the negotiations being mediated on the Egyptian side by Morsi and General Mohamed Shehata, head of Egypt's General Intelligence Directorate, talks had originally focused on a two- to three-stage ceasefire.

The first stage was to have been what is known as a "temporary lull" or tahdiya in Arabic followed by a hudna – a truce or calming period which it had been hoped would set the scene for a longer-term agreement on issues relating both to the blockade of Gaza and assassinations of Hamas figures on one side and Israeli security demands regarding rocket fire on the other.

During Tuesday afternoon and evening that process began unravelling as both sides came under internal pressure to achieve what has proved so difficult before: to come to a comprehensive settlement in one go.

Within hours both sides were accusing the other of not replying to ceasefire proposals, while some in Hamas were suggesting they had not been kept in the loop by the Egyptian government.

"The Israeli side has not responded yet, so we will not hold a [news] conference this evening and must wait until tomorrow," Ezzat al-Rishq, a senior Hamas leader, told Reuters on Tuesday night.

The same message was being delivered by a Hamas official in Beirut, Osama Hamdan, who spoke to al-Jazeera. "The truce is now held up because we are waiting for the Israeli side to respond."

The reality, it emerged on Wednesday, is that both sides were facing internal opposition to the proposed ceasefire.

In Israel, according to some reports, a cabinet split saw the defence minister, Ehud Barak, prepared to accept the ceasefire originally on offer while the prime minister, Binyamin Netanyahu, and foreign minister, Avigdor Lieberman, were opposed.

That split, some analysts have speculated, may have as much to do with Israel's internal politics, with an election on the horizon, as the substance of any deal.

On the Palestinian side the argument was even more complicated, pitting factions within Hamas who were happy to accept a ceasefire against hardliners around Mohamed Deif, Hamas's military commander and other groups, who seek an immediate lifting of the blockade and opening of the Rafah border crossing.

In Hamas itself there has been growing competition both between the military side, which has taken increasing prominence, and the political wing, and between Khalid Meshaal, the main leader in exile, and the Hamas prime minister, Ismail Haniya.

"It appears the details had not been fully worked out on both sides," said one diplomat who has been following the negotiations. "Egypt wanted a staged approach to the ceasefire but it seems both parties moved towards wanting to negotiate something more comprehensive.

"The regional situation has become more complicated too," he added. "In the Mubarak era it was much more straightforward for Egypt to act as a mediator for ceasefires between Hamas and Gaza in Israel. Now it is more complex with Qatar and Turkey also part of the picture.

"Another complicating factor is that there is a new regime in Egypt, although both the security structures and the Muslim Brotherhood seem to be pulling in the same direction on this."

In particular Israel is believed to have wanted guarantees from Egypt about arms smuggling through the Sinai to Gaza and security guarantees that were difficult for Cairo's new Muslim Brotherhood-led government to make.

Escalating security problems with Salafist groups in the northern Sinai, already heavily militarised, has challenged Egypt's capacity to respond.

Indeed, on Wednesday, as if to underline the problem, Egyptian authorities seized pick-up trucks carrying 108 warheads for Soviet-designed Grad rockets smuggled from Libya, believed to be bound for Sinai or Gaza.

Egypt is also cautious of being asked to take security and economic responsibility for Gaza, which it fears could be used by Israel to make steps towards a two-state solution to the Israel-Palestine conflict more difficult, not easier.