In recent months, the clans have been accused of looting aid trucks as well as committing murders and carrying out kidnappings.
At least two of the major clan groups include members who have either actively fought alongside Islamic State, or declared allegiance to the terrorist organisation.
Senior US military commanders are concerned that Trump’s peace process “will not work without reliable security partners”, one source told the Telegraph.
Britain, France and some other nations involved in trying to turn the President’s 20-point peace plan into reality have also expressed concern.
Four months after the ceasefire, plans for a post-Hamas police force appear largely to have stalled, amid disagreement over its composition and funding. There is also significant uncertainty as to whether Hamas would voluntarily disarm.
Trump is holding the inaugural meeting of his Board of Peace in Washington this week, which delegations from more than 20 countries will attend.
Organisers hope to announce funding commitments for the reconstruction of Gaza, as well as promises of troops for the United Nations-mandated international stabilisation force (ISF), which, it is thought, would sit above the new Gaza police force and liaise with the Israel Defence Forces outside the Strip.
Trump said that US$5 billion ($8.3b) had already been pledged for reconstruction and “thousands” of personnel promised to the ISF and local police.
The plan to recruit the new police force from the clans emerged before Christmas, prompting disagreement at the multi-national new Civil-Military Coordination Centre in southern Israel.
One Western source said: “There was significant pushback along the lines of ‘this is ridiculous – they’re not only criminal gangs but they’re sponsored by Israel’.”
Jared Kushner, Trump’s son-in-law, is central to the administration’s drive to push forward the 20-point plan for peace.
He has been spearheading plans for new temporary “safe” communities in the part of Gaza under IDF control to tempt Palestinians away from the Hamas-controlled area, in the event the terrorist group does not willingly disarm.
The first community, which is currently being constructed on site of the former city of Rafah, is in an area dominated by the “Popular Forces” militia, an Israeli-backed group that has been accused of drug smuggling and aid looting.
Its former leader, Yasser Abu Shabab, who denied involvement in organised crime, was murdered in an internal disagreement in December.
Kushner has been working closely with Aryeh Lightstone, chief executive of the Abraham Accords Institute, who is said to be ideologically aligned to the Israeli position on security and opposition to a Palestinian state, according to sources.
He co-ordinates much of the informal planning on the future of Gaza from a beachfront hotel in Tel Aviv, including discussions with billionaire investors, leading one source to call the discussion group the “Hilton club”.
Western officials are questioning the practicality of what they describe as Kushner and Lightstone’s “ideological” approach.
One official told the Telegraph: “There is a feeling that Kushner, Lightstone et al believe that if they can just give Palestinians the chance to flee Hamas, then they will take it.
“But the reality on the ground is that while lots of Gazans don’t like Hamas, they really don’t like or trust the clans. They see them as criminals.
“There is also a concern that the more ideological members of the administration will at some point turn around and say ‘we’ve given you the opportunity to leave Hamas; if you’re still there you must be a sympathiser’. Then Israel gets the green light to restart the war.”
Which clans US and Israeli figures proposed hiring from for the new Gaza police force is not currently known.
However, the White House did not deny that it had proposed this approach.
Reports from organisations such as the International Crisis Group from nearly 20 years ago detail concerns about drugs trafficking and weapons smuggling.
Figures within the Popular Forces, such as Isam Nabahim – a senior commander – are believed to have fought with Islamic State in the Sinai against Egypt.
The Doghmush clan in Gaza City is also accused of having had links with the terror group.
Although never proven, the clan was suspected of helping to hold the Israeli soldier Gilad Shalit, whom Hamas abducted in 2006, as a prisoner.
His release in 2011 has subsequently been seen as a strategic security failure, because Israel was forced to release more than 1000 Palestinian prisoners – including Yahya Sinwar, the mastermind of October 7 – in return.
A group called the Army of Islam, which was led by figures from the Doghmush, also abducted the BBC correspondent Alan Johnston, who was held for 114 days in 2007.
Some Israeli media have reported that, towards the beginning of the Gaza war, the various groups were given assistance from the general security force of the Palestinian Authority (PA) in Ramallah, allegedly with CIA assistance.
However, Israel then took over the relationships.
Israel’s involvement with the Popular Forces became public last May after a senior official, who was believed to oppose the arming of Palestinian groups, leaked the details.
Hossam al-Astal, who leads an armed group to the east of Khan Younis, told the Telegraph in October that he “co-ordinated” with Israel, and that he would be prepared to help secure a post-Hamas Gaza.
The former security official in the PA – from which Hamas seized power in Gaza in 2007 – is one of a number of leading “clan” figures who had been in prison in Gaza at the beginning of the war, but escaped when Hamas jailers fled their posts.
There has been speculation that the Board of Peace, through its subordinate National Committee for the Administration of Gaza, has selected Jamal Abu Hassan, a former PA security chief in Khan Younis, to lead the new police force.
A Western official said that a more recent iteration of the US policing plan had proposed “agnostic recruitment”, where members could come from the clans, from the former PA security forces in Gaza, or elsewhere.
“The process has lost energy at the moment,” he said. “You can’t get past the fact that without a trustworthy force on the ground the process is destined to fail.”
A US administration official told the Telegraph: “Planning efforts remain underway to develop the vetting process for the police force. We won’t get ahead of that process.
“As the president stated, Hamas must uphold its commitment to fully and immediately demilitarise.”
The Israeli Prime Minister’s office declined to comment.
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