Students and opposition party demand French president withdraw cost-cutting measure as he’s accused of targeting poor.

The French president Emmanuel Macron has come under fire for cuts to housing benefits, just as his popularity has dropped in polls.

A row erupted on Monday after the government announced it was going to cut a particular type of housing benefit by five euros a month in a move affecting millions of French people – including many living below the poverty line.

Louis Gallois, head of a federation of organisations working on poverty, slammed the measure for “hitting the poorest people foremost”.

More than 800,000 of those affected were students, causing students’ unions to demand the government “instantly withdraw” the plans. Disgruntlement among students is a thorny issue because the government is seeking to avoid students joining potential protests against Macron’s proposed changes to labour laws this autumn.

The government spokesman Christophe Castaner said the measure was justified because France needed to rein in its public spending and bring down its deficit. The government said the housing benefit cuts had been decided under the previous Socialist president, François Hollande, which Socialist ministers angrily denied.

Opposition politicians accused Macron of targeting the poor and favouring the rich with measures including the loosening France’s wealth tax so that it applies only to property, not investments – which Macron has argued will boost the economy. A study last week found that overall the richest 10% of France’s households will likely benefit the most from Macron’s proposed tax cuts.

The housing benefit issue is the latest row over Macron’s drive to cut public spending and bring down the deficit with the aim of meeting EU rules for the first time in a decade.

Earlier this month, Macron was accused of betraying his manifesto promises by putting off promised tax cuts. The prime minister, Edouard Philippe, had said key tax cuts would be delayed while France cut spending because it was dancing on a “debt volcano”.

After an outcry, Macron made a swift U-turn and the cuts will now begin to come into force next year. But the saga was damaging because it left the government vulnerable to criticisms that some election promises might not be kept.

Before the row over housing benefit, Macron – a centrist political newcomer who beat the far-right Marine Le Pen to win the presidency in May – saw his popularity drop 10 percentage points to 54% in an Ifop poll published in the Journal du Dimanche, echoing another recent poll by BVA.

It is rare to see such a marked drop so soon after an election. The last president to drop so fast was Jacques Chirac in 1995. At this stage – less than 100 days after election – previous presidents, the Socialist François Hollande and the right’s Nicolas Sarkozy, were polling higher, before their own satisfaction ratings later plunged and they failed to get re-elected.

Macron’s camp brushed aside the poll, saying an initial dip in popularity was to be expected because France’s youngest president in modern times wanted to get started on structural reforms, including loosening labour laws and overhauling the pensions and unemployment system. “When you reform, you take the risk of a moment of being disliked,” said one pro-Macron parliamentarian.

It was clear that it was Macron’s policies and economic decisions since taking office — rather than simply his personality — that were causing him the biggest challenge among voters. His prime minister, Edouard Philippe, tasked with putting Macron’s plans into place, also fell in popularity.

The resignation last week of France’s military chief after a bitter row over cuts to defence spending led to Macron being accused by some generals of having an “authoritarian” style.