KABUL: Opponents of Afghan President Hamid Karzai are scrambling to unite behind a single leader in a last-minute bid to field a unified team for the Aug 20 election, the brother of one of the main hopefuls said yesterday.

Karzai registered for the poll on Monday with a former opposition leader as one of his two vice-presidents.

Other candidates have until Friday to sign up, but the opposition has so far struggled to come up with a ticket that might command broad enough support to effectively challenge him.