Emmanuel Macron’s closest special adviser has become the latest to quit the Élysée Palace as the French president reshuffles his team to counter the gilets jaunes anti-government protests and an ongoing scandal around a former security aide.

Ismaël Emelien, 31, had helped mastermind the 2017 election campaign in which Macron promised a mix of right- and leftwing ideas that would destroy France’s tired political party system. Emelien took the role at the Élysee after Macron’s defeat of the far-right Marine Le Pen in 2017, advising on how the now-president could continue to “disrupt” traditional politics.

The president is now making changes to his inner-circle. Macron’s young team has been accused of being caught off guard when the gilets jaunes (yellow vest) fuel tax revolt began in November and quickly morphed into a widespread protest against the executive.

This close-knit group of mainly young, male advisers, dubbed “The Mormons”, were seen as clever at digital messaging and strategy but distant from on-the-ground politics.

Emmanuel Macron’s team, including Ismael Emelien (pictured fourth left), arrive at the Élysée Palace in May 2017 before the handover ceremony for the new president. Photograph: Yoan Valat/EPA

Emelien said he would leave in late March because he wanted to take a more public role and promote a book about progressive politics.

His name had recently surfaced in an investigation into Alexandre Benalla, Macron’s former security adviser, but both Emelien and the president’s office said the departure had nothing to do with a scandal that continues to trouble the executive.

The scandal blew up last summer when footage emerged of Benalla illegally dressed as a police officer and beating protesters on the edge of a May Day demonstration, despite having no police background or training. He was eventually sacked but there was outrage from opposition parties who accused the Élysée of attempting to cover up the scandal.

The row intensified after it emerged that Benalla had continued to travel on diplomatic passports after he was fired. He has since been charged with illegally using diplomatic passports.

In a recording taped after his sacking and published by the investigative website Mediapart, Benalla was also heard discussing the support he continued to enjoy from administration figures, including Emelien. French prosecution officials attempted to search Mediapart’s office, but editors refused them entry.

Benalla is under renewed scrutiny after a Mediapart investigation into security contracts worth €2.2m (£1.9m) that he may have brokered with two Russian oligarchs close to Vladimir Putin, before and after he left the Élysee, potentially misleading a senate committee hearing about his role.

French prosecutors said on Friday they had opened a corruption investigation into one of the contracts, concluded with the Russian tycoon Iskander Makhmudov.

In another twist to the ongoing saga, the prime minister Édouard Philippe’s head of security resigned following media revelations that she and her partner had welcomed Benalla to their home in July.

Marie-Elodie Poitout denied any wrongdoing, saying she and partner Chokri Wakrim had simply met with Benalla, whom they knew socially. She asked to be moved to another job so as not to stir up further political controversy.