How much power will Iran's new president actually wield?

Reformist-backed cleric Hassan Rouhani has won Iran's presidential election, securing just over 50% of the vote and so avoiding the need for a run-off.

However any reforms could face a system of "gridlock" from the religious establishment, explains the BBC World Affairs Editor John Simpson.

But he says that the non-elected Supreme Leader Ayatollah Ali Khamenei may "feel it possible to shift a little bit".