Palestinian leader Mahmoud Abbas gave Fatah and Hamas a deadline on Thursday to end their deadly rivalry, failing which he would call a referendum which could lead to a new national unity government. Abbas’s shock announcement came on the first day of cross-party talks aimed at drawing a line under divisions between his Fatah movement and the Islamists of Hamas, who now head the government after winning a January election.The so-called national dialogue in Ramallah was called in the face of an upsurge in violence between Fatah and Hamas that has left 10 people dead since the beginning of the month. As widely expected, both Abbas and Hamas Prime Minister Ismail Haniya urged the armed groups to stop turning their guns on each other and avoid a descent into civil war. But Abbas’s warning that they had 10 days to agree on a common platform or he would submit to a referendum a proposal from jailed faction leaders on how to end the Palestinian crisis caught everyone off guard. “If not, I will submit the document to a referendum in 40 days,” he said.