Young activists in the ruling Palestinian Fatah party have broken off to form their own faction under the leadership of jailed uprising leader Marwan Barghouti.
The move, which deals a bitter blow to Palestinian leader Mahmoud Abbas, boosts the electoral prospects of Hamas militants ahead of January parliamentary elections.
Fatah officials were negotiating feverishly with Mr Barghouti and his associates today in an effort to keep them in the party.
Palestinian negotiator Saeb Erekat said the Fatah list would be reworked to put young activists - and not just Mr Barghouti - in top spots where chances of election are best.
But Barghouti supporters said he was determined to contest the January 25th vote on a separate slate after Mr Abbas stacked the top of the Fatah list with corruption-tainted old-timers, largely disregarding the results of primaries that young activists won.
Local elections today in 42 West Bank towns, including the cities of Nablus and Ramallah, were likely to be a barometer of the split's effect on the parliamentary vote.
The Islamic militant group Hamas is hoping to capitalise on the disarray in the ruling party. Mr Barghouti, serving five life terms in an Israeli prison for involvement in deadly attacks, has emerged as the most popular Fatah leader in West Bank primary elections.