By Barbara Plett BBC correspondent in Jerusalem

Hamas aims to exploit Palestinian fears about the peace deal

"We have no confidence that [Palestinian Prime Minister] Mahmoud Abbas can lead the Palestinians," a Hamas political leader, Ismail Abu Shanab, told the BBC.

"We understand that he cannot achieve any of the Palestinian hopes, so he's not the right man; we will not continue the talks."

This undermines the prime minister's strategy for meeting his roadmap commitment to end Palestinian violence.

Mr Abbas - better known as Abu Mazen - was trying to negotiate a ceasefire with the militias, aware that the Palestinian Authority (PA) is too weak to disarm them by force.

Dashed hopes

By most accounts, the talks showed promise of success.

That is, until the summit in Aqaba, Jordan, this week that formally launched the roadmap, attended by Abu Mazen, US President George W Bush and Israeli Prime Minister Ariel Sharon.

It remains to be seen whether the ceasefire talks can be resurrected, but even if Abu Mazen gets the show back on the road, the question is where it will lead

The Palestinian prime minister won tributes from both the US and Israel for his call to end the armed Palestinian uprising.

He believes this is now the only way the Palestinians can expedite international pressure to get Israel out of the West Bank cities and again allow the PA to become a functioning government.

But Hamas criticised his pledge to do so with no guarantees from Mr Sharon to end the occupation, and his equation of Palestinian violence with terrorism rather than resistance to occupation.

Crucially, it also gave voice to a broader dissatisfaction with Abu Mazen's ability to achieve Palestinian national aspirations.

Like Hamas, many Palestinians were alarmed by his failure to mention their standard demands, such as East Jerusalem as the capital of a future state and the right of Palestinian refugees to return to what is now Israel.

Grassroots support

Hamas' position is a problem for Abu Mazen, because it is not simply a military wing.

Hamas accuses Abu Mazen (right) of making too many concessions

The Islamic movement has a lot of popular support based on a network of social services that supply much needed aid to thousands of people, in stark contrast to the inefficiency and collapse of Palestinian Authority institutions.

Hamas also received implicit support from the Palestinian leader Yasser Arafat, who denounced the Aqaba summit for delivering no tangible gains.

It remains to be seen whether the ceasefire talks can be resurrected, but even if Abu Mazen gets the show back on the road, the question is where it will lead.

Road to nowhere?

George W Bush's peace summits - in Aqaba and with Arab leaders in Sharm el-Sheikh - left many Palestinians with the uneasy feeling that the terms of reference for the peace process had changed.

Hamas received implicit support from Yasser Arafat

The American sponsor was no longer talking about trading land occupied by Israel in 1967 for peace, a formula established in the 1991 Madrid peace conference.

The goal seemed to be a more modest "viable" Palestinian state with "contiguous territory".

This, it seemed, was to be achieved not in the name of national rights, but to the extent the Palestinians fight "terrorism", framing the peace process within America's war on terror.

In halting the ceasefire talks, Hamas is aiming to exploit these Palestinian fears.

To overcome them, Abu Mazen will have to convince all his people, not just Hamas, that the goal remains an end to the occupation that began in 1967, even if the means should now be negotiations rather than the armed intifada.