 The friction blew into open division when Shapour Bakhtiar, one of the three top leaders, accepted the Shah's invitation to become the prime minister of Iran, but only on the condition that the Shah committed himself to reign and not rule.Bakhtiar's decision to collaborate with the Shah caused the National Front to denounce him as a traitor to their cause and to expel him from the organization.Only a few moderate and secular individuals among the leadership chose to ally with Bakhtiar and with the monarchy.