Hamas and Islamic Jihad, the two main Palestinian Islamist movements, are holding talks about merging their two factions, sources from both movements said Tuesday.

At a meeting with top officials from Islamic Jihad, Gaza's Hamas-affiliated prime minister, Ismail Haniya, called for "opening a serious dialogue to achieve the merger of the two movements," his office said in a statement.

Islamic Jihad confirmed that talks to merge the two factions were already underway.

"An in-depth dialogue has actually begun, both internally and externally, with the aim of uniting," Islamic Jihad spokesman Daud Shihab told AFP, referring to the group's leadership which, like Hamas, is based in both Gaza and Damascus.

All previous attempts to merge the two Islamist movements had ended in failure, Shihab noted.

He indicated that the current talks were taking place "at the highest level" among the leaders of both factions in Gaza and Damascus, as well as among Islamist prisoners currently being held in Israeli jails.

Uniting the two movements would be "in the interest of both the Palestinian cause and the future of the Palestinian liberation movement, particularly in light of the Arab Spring," Shihab said.

The latest statements represent the first time for Hamas and Jihad to speak publicly about merging.

The two factions have long held opposing views on government, with Jihad boycotting the last Palestinian elections in 2006 that were swept by Hamas.

The initiative to explore a merger comes as Hamas and its Fatah rival, which dominates the West Bank-based Palestinian Authority, struggle to implement a reconciliation deal signed in April 2011 that has made little progress on the ground.

There are also moves to reform the Palestine Liberation Organisation (PLO), which is internationally recognised as the sole legitimate representative of the Palestinian people, to allow Hamas and Islamic Jihad to join it.

It also comes in the wake of a series of electoral successes for Islamist parties in Egypt and Tunisia following the political upheavals brought on by the Arab Spring.