PARIS (Reuters) - France’s budget rapporteur on Thursday asked the government to spell out how much the rich stood to gain if a wealth tax was scrapped, as unease over President Emmanuel Macron’s plan within his own party bubbles up.

French President Emmanuel Macron delivers a speech during a special congress gathering both houses of parliament (National Assembly and Senate) at the Versailles Palace, near Paris, France, July 3, 2017. REUTERS/Eric Feferberg/Pool

Macron made good in early October on a campaign pledge to abolish the tax, earning him a “president of the rich” tag among critics.

Joel Giraud, a lawmaker from Macron’s Republic on the Move (LREM) party in charge of steering the 2018 budget bill through the lower house, sought details of how the wealthiest 1 percent would benefit.

“In the light of the discussion of the 2018 budget law, it would be particularly useful for me to have a study of the impact of the tax and budget measures on the wealthiest French,” Giraud said in a letter to Finance Minister Bruno Le Maire, seen by Reuters.

Le Maire had on Wednesday declined to respond to a similar request from the opposition.

The LREM’s lawmakers, who hold a clear majority of 313 in the 577-strong assembly, have largely toed the party line since June, conscious of how closely their fortunes and Macron’s are linked.

But with Macron’s approval ratings on the wane and polls showing four in five French voters consider his policies slanted towards the rich, LREM lawmakers -- many of whom initially come from the left -- have started making their voices heard.

Last week they proposed an amendment to the budget bill to increase taxes on luxury yachts and precious metals.

One of them, Brigitte Bourguignon, a former Socialist who heads parliament’s social affairs committee, last week told Le Parisien newspaper that she was one of a number who were pushing the government to do more on welfare, though she insisted she was no rebel.

The 2018 budget aims to cut both taxes and spending as France seeks to restore its fiscal credibility with its European neighbors.

Macron’s Socialist predecessor Francois Hollande saw much of his reform program undermined by rebellion within his party.