Brazil’s far-right president, Jair Bolsonaro, has signalled he may abandon controversial plans to make his son ambassador to the United States, amid a fierce political backlash and growing signs Congress may block the move.

“I’m not going to subject my son to failure,” Bolsonaro told reporters on Tuesday in what was the first public hint he may be reconsidering his nomination.

Bolsonaro’s bid to hand control of Brazil’s Washington DC embassy to his 35-year-old son, Eduardo, has outraged Brazil’s foreign service and set off a domestic political firestorm.

A report prepared for senators who need to approve Bolsonaro’s move concluded it amounted to nepotism and identified three distinctly undemocratic precedents where leaders had made their children ambassadors: in Saudi Arabia, Chad and Uzbekistan.

Eduardo Bolsonaro’s appointment must be approved by a simple majority in Brazil’s 81-member senate, where such proposals are seldom challenged. But there are growing indications senators may block the nomination.

This week, 29 senators told the Estado de São Paulo newspaper they would reject Bolsonaro’s move, while only 15 declared support. Of the remaining 36 senators with a vote, seven were undecided and 29 declined to comment.

“They are having difficulty they were not expecting,” said Thiago de Aragão, a political analyst.

“The presidential palace is calculating and monitoring [the situation] very closely. If they make a decision to call the vote, it’s because they feel secure with the result.”

On Tuesday afternoon, Eduardo Bolsonaro rejected speculation his father was rethinking his nomination. “I feel confident and hopeful,” he was quoted as saying.

Jair Bolsonaro claims his son’s ties to the Trump clan would be a boon to US-Brazil ties. The Bolsonaros are enthusiastic Trump supporters, with Eduardo sporting “Trump 2020” and “Make Brazil Great Again” caps during a recent trip to Washington.

Eduardo Bolsonaro is also the South American representative of the Movement, the far-right group created by Trump’s former chief strategist Steve Bannon.

But Bolsonaro’s plan has triggered an outcry of disapproval from across the political spectrum.

“It is a flagrant case of nepotism, unprecedented in the history of the Republic. It is an indecency, a mockery – it is outright nepotism,” said Randolfe Rodrigues, the opposition leader in the senate.

Bolsonaro has been unapologetic. “I intend to benefit my son, yes. If I can give my son filet mignon, I will,” the rightwing populist said last month.

Eduardo Bolsonaro, an elected congressman, has been ridiculed for claiming the fact he had “fried hamburgers in the United States” during a study abroad program qualified him to be Brazil’s ambassador.