Turkey’s president on Friday vetoed an amendment to the constitution that would have led to the direct election of his successor in the latest move to keep a former Islamist from becoming head of state.

The government, which has its roots in political Islam, proposed the change after failing to get parliament to appoint Abdullah Gul, foreign minister, to the post. Turkey’s military objected to his candidacy because of his Islamist background, initiating the country’s most serious political crisis in a decade.