France’s interior minister, Gérard Collomb, has announced he will resign next year to run for his former job as mayor of Lyon, in yet another blow to the president.

The announcement from Collomb, a political heavyweight and one of Emmanuel Macron’s most loyal ministers, comes after the environment minister, Nicolas Hulot, quit last month and as the president’s approval ratings have plummeted.

Collomb told L’Express magazine he would quit after the European elections in order to stand for mayor of France’s third biggest city in 2020.

“The local elections are still far away – I will run in Lyon if I don’t get diagnosed as seriously ill any time before that,” he joked. “I won’t be interior minister right up until the last moment. After a certain amount of time it would be better to be totally free for the campaign.

“I think ministers who want to run in the 2020 local elections should be able to quit the government after the European fight,” he said of the European parliament polls in May.

Collomb served as Lyon mayor for 16 years until Macron poached him for the interior ministry job.

The news comes after Alexandre Benalla, one of the president’s top security officers, was filmed hitting and stamping on a man at a Paris protest while dressed as a police officer.

Macron was elected in May 2017 on a promise to reinvigorate the economy. However, pro-business policies such as tax cuts for the wealthy have yet to bear much fruit, and growth forecasts have been cut to 1.6% this year.

The president, a former investment banker, was criticised last week for telling an aspiring gardener he could find him a job in a restaurant or hotel “just by crossing the street”.

A Kantar Sofres Onepoint poll published on Monday found only 19% of French people had a positive view of Macron, 60% expressed a negative opinion.