House of Representatives (HoR) head Aguila Saleh and High State Council (HSC) head Khaled al-Mishri left for Morocco early in the morning and were hoping to wrap up an agreement, an HoR member and Meshri's spokesperson said.
The two would likely present any deal as a major breakthrough after months of paralysis - U.N. envoy Adoulaye Bathily has said there could be national elections by the end of the year if a deal is reached this month.
However 61 HoR members and some HSC members have already objected to the way their leaders have been negotiating their agreement, and have said they will oppose its ratification.
Disputes over fundamental constitutional issues including the role of a president and parliament, and over key questions of electoral law including the eligibility of divisive candidates, have long challenged Libya's political process.
The country has had little peace or security since the 2011 NATO-backed uprising that ended four decades of rule by Moammar Gaddafi. Libya split in 2014 between warring eastern and western factions that still control most territory.
Since the main factions agreed a ceasefire in 2020, peace efforts have focused on pushing for national elections to create governing institutions with broad political legitimacy that the existing bodies are widely seen to lack.
The HoR was elected as a national parliament in 2014 to a four-year term. The HSC was created as part of a political agreement in 2015 from members of an earlier interim parliament elected in 2012.
The Government of National Unity in Tripoli under Prime Minister Abdulhamid al-Dbeibah was created in 2021 as part of a U.N.-backed process, but it was only supposed to govern until national elections that were planned for the end of that year.