Aid agencies fear the Israeli government will stop them from delivering lifesaving programs in the Gaza Strip in the new year, using new registration requirements for international humanitarian organisations.
Israel's Ministry of Diaspora Affairs and Combating Antisemitism has introduced rules for aid organisations, including that they must not engage in any activities or criticism which "delegitimise" the state of Israel.
Aid groups said many of the new requirements were essentially political and sought to prevent or silence criticism of Israel's conduct in Gaza, which the Israeli government still prevents the international media from accessing without military escort.
"The first one is that we must recognise Israel as a Jewish and democratic state," Bushra Khalidi, the policy lead for Oxfam in the occupied Palestinian Territories.
"Another one of these requirements in the new registration rules are about basically not carrying out delegitimising activities against Israel.
"We do not know what delegitimising activities means. It's not defined in the procedures. So that could be very much interpreted very vaguely. It's politicised. It's an opaque criteria.
"It means that if we are to report against on aid obstruction, on harm done to our colleagues…So if we were to monitor and report that that would be a reason to refuse us registration or deregister us from Israel. And so basically it restricts our access, but also is meant to almost silence us."
Aid organisations said they were also required to submit the details of their staff and the families of staff members, including identity documents, something they are afraid to do because Israel killed hundreds of aid workers during the war.
"(This) is something that we would not usually and normally do and in the circumstances where Israel has harmed over 500 humanitarian workers, including their families, you know, we would not be in a position to do that because of the duty of care that we owe to our staff and our colleagues in Gaza, but also all across the Palestinian territory," Ms Khalidi said.
Aid agencies provide many of the essential services in Gaza, where Israel's bombardment and invasion during its two-year war against the militant group Hamas have destroyed most of the housing and infrastructure.
The Humanitarian Country Team, a United Nations-led body that brings together UN agencies and more than 200 aid organisations working in the occupied Palestinian territories, said Israel's new law "fundamentally jeopardises the continuation of humanitarian operations throughout the OPT".
"The system relies on vague, arbitrary, and highly politicised criteria and imposes requirements that humanitarian organisations cannot meet without violating international legal obligations or compromising core humanitarian principles."
In a statement, the Israeli Ministry of Diaspora Affairs and Combating Antisemitism said the restrictions were designed to stop any "hostile actors" from "operating under a humanitarian cover".
It said: "The Ministry works to assist genuine humanitarian organisations and at the same time acts decisively against entities connected to terrorism, antisemitism, delegitimisation of the State of Israel, persecution of IDF soldiers, Holocaust denial and denial of the crimes of October 7 (the Hamas terrorist attacks in southern Israel)."
The Ministry, via Israel's Ministry of Foreign Affairs, did not respond to specific questions about the potential impact of the rules or why it was applying political criteria to operations by established international humanitarian organisations.
Many aid groups left in the dark
Many groups said they had not been told if their applications were successful, meaning they were approaching the December 31 deadline for the new registrations without knowing if they could continue operations in the new year.
One agency awaiting registration is Doctors Without Borders, which provides many of the medical services inside Gaza.
"We don't know what's going to happen to our activities from January 1st onwards," the agency's Gaza emergency coordinator Pascale Coissard told the ABC.
"We're not sure if we will be able to continue to work in Gaza in 2026 and if we lose access to Gaza and also actually the West Bank and East Jerusalem, a large portion of the people in Gaza and elsewhere in in West Bank would lose access to critical medical care and water and life-saving support."
Other established organisations, such as Save the Children, have reportedly been refused registration.
The Ministry of Diaspora Affairs says 14 of the 100 applications for registration received by the end of November had been rejected, with the others either approved or under review.
It did not clarify how many had been approved.
Pascale Coissard from Doctors Without Borders said denying entry to established organisations could exacerbate the humanitarian crisis in Gaza.
"In Gaza right now, Doctors Without Borders is currently supporting six public hospitals (and) we run two field hospitals," she said.
"So if we lose access to Gaza, it's going to be quite a disaster for the Palestinian population there.
"(The year) 2026 Is going to be very important for Gaza because it (the war) is not over, it's not because there is a ceasefire agreement that everything is fine in Gaza. With the winter, we can see how people are suffering.
"They have no access to proper shelter. All the houses have been destroyed, almost all of them… and we have provided a lot of services in healthcare and water that are going to be very necessary for the survival of people in 2026, which is why our access continues to be so important."