NAIROBI      -     Ethiopian Prime Minister Abiy Ahmed, winner of the 2019 Nobel Peace Prize on Friday for ending 20 years of hostility with neighbouring Eritrea, can arouse strong reactions at home.

During a meeting at Ethiopia’s foreign ministry in July, officials were shocked by social media reports that their prime minister was visiting Eritrea. No one in the room had been informed of Abiy’s trip, his second since clinching his peace deal last year.

“The foreign office was not in the loop,” said a senior official who was present. “We learned of it from the Eritrean media, on Facebook and Twitter.”

The surprise visit is typical of Abiy, who both fans and critics say often relies on bold personal initiatives and charisma to drive change instead of working through government institutions.

Nebiat Getachew, the foreign ministry spokesman, said policy was well co-ordinated. He did not confirm if Abiy had made the July trip without informing the ministry.

But Abiy’s unpredictable style annoys some Ethiopians. It is unclear how much of the fractious ruling coalition backs his reforms, or how durable they would be without him. He has already survived one assassination attempt: a grenade thrown at a rally last year.

Lasting change cannot be built through a “cult of personality”, said Comfort Ero, Africa programme director at the International Crisis Group think tank. “None of Abiy’s promised transformational reforms are going to have any solid foundations unless he works through the institutions,” she said.

Ethiopia has been among Africa’s fastest growing economies. But uncertainty over Abiy’s ability to carry out all his reforms worries both Ethiopians and foreign investors.

Some observers say Abiy, a former military officer, will sometimes bypass ministries because his reforms will otherwise become mired in bureaucracy. Those reforms - including unbanning political parties, releasing imprisoned journalists and prosecuting officials accused of torture - have drawn ecstatic crowds at rallies.

“Abiy seems to have relied on his charismatic rule,” said Dereje Feyissa, a professor at Addis Ababa University. “The question is whether this is sustainable. Euphoria is subsiding.”

Other observers say Abiy’s rapid changes are a deliberate attempt to wrong-foot opponents from the previous administration, which was dominated by Tigrayans. Abiy, 43, is from the Oromo group, which spearheaded the protests that forced his predecessor to resign.