AS HE struggles to realise a Palestinian state, pressures are mounting on Mahmoud Abbas, the Palestinians’ ageing president. They come from among his own people. His erstwhile security chief, Muhammad Dahlan, has turned on his former master, accusing him of complicity in poisoning his predecessor, Yasser Arafat, of promoting his two sons to the pinnacle of a kleptocracy and of throwing Palestine’s future away by engaging in futile negotiations with Israel. Senior Palestinian intelligence men have joined Mr Dahlan’s side. So, too, have powerful sponsors in the United Arab Emirates’ royal court and among Egypt’s generals, who see Mr Dahlan as the leader of the Palestinian flank in their regional war on the Muslim Brotherhood.

Mr Abbas’s loyalists emblazon the front pages of Palestine’s press with banners pledging support, but Mr Abbas looks increasingly irked. When he assembled 120 senior people for a pep-talk on March 10th, a week before he was to meet Barack Obama in Washington, he devoted over half of his speech to denouncing Mr Dahlan. He accused him of feeding Mr Arafat poisoned pills, acting as Israel’s informant in a spate of assassinations and surrendering Palestine’s seaside enclave of Gaza to the Islamist movement, Hamas, in a botched military campaign in 2007. To ward off the risk of a coup, Mr Abbas recently cut the pay of around 100 pro-Dahlan men in his security forces, and set up a star-chamber to purge the ranks of his own Fatah movement.

Mr Abbas had already chased Mr Dahlan out of Palestine and expelled him from Fatah in June 2011, but from his seat in Abu Dhabi his rival refuses to fade. On March 16th, the night before Mr Abbas’s White House meeting, Mr Dahlan appeared on Egyptian satellite television, promising to challenge Mr Abbas on his return. In recent days gunmen have opened fire on the homes of Mr Abbas’s security advisers and ministers in the Palestinians’ administrative capital, Ramallah; they have also challenged Mr Abbas’s representatives in Jordan’s Palestinian refugee camps and killed a senior Abbas man in Lebanon.

Mr Abbas’s Western-trained security forces have so far proved adroit at curbing unrest and rounding up troublemakers, at least in the West Bank’s city centres. But they are less able to thwart another of Mr Dahlan’s game-plans: staging a comeback in Hamas-ruled Gaza, where he was born. Desperate to lift the grinding siege still imposed on them by both Egypt and Israel, Gaza’s Islamists are said to have offered their old foe a deal: use your close ties with Egypt’s generals to reopen the border between Gaza and Egypt, and we will let you return. As a sweetener, they have freed seven of Mr Dahlan’s men from prison.

Mr Abbas abolished parliament seven years ago and has since ruled by decree as a supposedly benign dictator with barely a semblance of accountability. His own four-year term expired in 2009. Though 78, he has refused to appoint a deputy, leaving loyalists as well as foes jostling for the succession. Set against Mr Abbas’s white hair and plodding demeanour, 53-year-old Mr Dahlan, with his black locks, looks young and dynamic. Without elections to decide Palestine’s leadership, the succession battle may take other, more brutal forms.