Khatami presented the so-called "twin bills" to the parliament during his term in office, these two pieces of proposed legislation would have introduced small but key changes to the national election laws of Iran and also presented a clear definition of the president's power to prevent constitutional violations by state institutions. Khatami himself described the "twin bills" as the key to the progress of reforms in Iran. The bills were approved by the parliament but were eventually vetoed by the Guardian Council.