Hamas is pressing Israel to include prominent Palestinians in a prisoner-release list as part of a ceasefire deal that will also see hostages returned from Gaza.
Hamas's insistence comes after the Israeli justice ministry published the names of 250 prisoners to be freed, but excluded seven high-profile prisoners, including Marwan Barghouti and Ahmad Saadat.
The men, who are serving sentences after being convicted of involvement in separate deadly attacks in Israel, have long been seen by Palestinians as symbols of resistance.
Twenty Israeli hostages are expected to be released before 12:00 (09:00 GMT) on Monday as part of the deal proposed by US President Donald Trump.
A senior Palestinian official familiar with the talks told the BBC that US envoy Steve Witkoff had promised to raise the exclusion of the Palestinian prisoners with Israeli Prime Minister Benjamin Netanyahu, but Israel has firmly refused to include them.
It is not clear whether this could be a sticking point, or impact the timeline for the release of hostages from the Gaza Strip and Palestinian prisoners held in Israeli jails.
The releases are due to take place in the first phase of Trump's ceasefire and hostage return deal, approved this week to end the two-year war in Gaza.
It is unclear how the hostages will be released this time - on previous occasions Hamas paraded them in public, infuriating Israel and many of its Western allies.
The bodies of deceased hostages will also be returned. It is thought that at least 26 hostages are deceased, with the fate of two others unknown.
Israel will also release about 250 Palestinian prisoners serving life sentences in Israeli jails, and another 1,700 Palestinians from Gaza who have been detained.
Hamas had submitted a list of prisoners it wanted released that included Barghouti and Saadat.
Barghouti is serving five life sentences plus 40 years after being convicted in 2004 of planning attacks that led to five civilians being killed.
Opinion polls have consistently indicated that he remains the most popular Palestinian leader, and that Palestinians would vote for him in a presidential election ahead of the current Palestinian Authority (PA) President Mahmoud Abbas or Hamas leaders.
Barghouti remains a senior figure in the Fatah faction that dominates the PA, which governs parts of the occupied West Bank not under Israeli control.
Saadat, leader of the Popular Front for the Liberation of Palestine (PFLP), was sentenced to 30 years after being convicted in 2008 of heading an illegal terrorist organisation and involvement in attacks, including the assassination of an Israeli minister in 2001.
In Israel, hospitals are preparing for the release of hostages as families await their return.