In this June 26, 2018, photo, French President Emmanuel Macron (right) and French Interior Minister Gerard Collomb arrive for a press conference following the President's first official visit to the Vatican at the French Embassy in the Holy See, Rome. (ALBERTO PIZZOLI / AFP)

PARIS — French Interior Minister Gerard Collomb, one of President Emmanuel Macron's closest allies, offered to step down on Monday but Macron refused to accept his resignation, Macron's office said. 

French President Emmanuel Macron's approval ratings have plunged to about 30%, from around 60% shortly after he was elected in May 2017

Two weeks ago, Collomb announced plans to quit the government and run for election as mayor of the eastern French city of Lyon in 2020, and indicated he would resign following European Parliament elections in May 2019.

"Following the attacks on the minister since he said he would be a candidate for the Lyon mayor post, the president has confirmed his confidence in him and has asked him to remain fully committed to his mission," an official at the Elysee presidential palace said, confirming a report on French daily Le Figaro's website. 

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A spokeswoman for Collomb confirmed that he had explained the motives for his resignation to Le Figaro. 

Le Figaro reported that Collomb, 71, had offered to resign because he did not want the interior ministry to be destabilised by his decision to run again for mayor of Lyon, a post he held from 2001 until 2017. 

Collomb, a former Socialist party stalwart who was one of the first top French politicians to join Macron's budding centrist party, had in recent weeks been critical of Macron, and had spoken of a "lack of humility" in Macron's administration. 

Macron's approval ratings have plunged to about 30 percent, from around 60 percent shortly after he was elected in May 2017. Critics say his policies favour the rich and his personal manner is often described as aloof and arrogant.

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Collomb has said big election victories tended to generate an atmosphere where leadership appeared to lose touch with voters' grievances. He has also lamented several mistakes, in particular the handling of a scandal involving an Elysee Palace security official, caught on camera beating up May Day protesters.