Mojtaba Khamenei, the second son of the assassinated Ali Khamenei, is being heavily tipped to succeed his father as supreme leader of Iran, which would pitch a hardliner into the task of steering the Islamic republic through the most turbulent period in its 48-year history and offer a powerful signal that, for now, it has no intention of changing course.

No official confirmation has been given and the announcement may be delayed until after the funeral of Ali Khamenei, which was on Wednesday postponed.

His son is believed to have been the choice of the Islamic Revolutionary Guard Corps (IRGC), and the Israeli defence minister, Gideon Saar, has warned he will be assassinated.

Ayatollah Seyed Khatani, a member of the Assembly of Experts, the body that chooses the new supreme leader, said the assembly was close to selecting a leader.

Rigid in his anti-western views, Mojtaba Khamenei is not the candidate Donald Trump would have wanted. Marco Rubio, the US secretary of state, said on Tuesday that Iran was run by “religious fanatic lunatics” – and Khamenei’s appointment is hardly likely to dispel that opinion.