One of France's top ministers, Sylvie Goulard, has resigned from her defence role less than a month after being given the job.
Her decision was linked to a French inquiry into claims that her centrist MoDem party wrongly used EU funds to pay party workers. She is a former MEP.
Her party is allied to the president's La République en Marche (LREM) party.
Ms Goulard is the second leading figure in President Emmanuel Macron's cabinet to leave ahead of a reshuffle.
One of the president's closest confidants, Richard Ferrand, announced his resignation from the cabinet on Monday after becoming ensnared in allegations that he had used insider information to secure a lucrative property deal for his wife while he was head of a mutual health insurance fund.
Macron's anti-sleaze campaign
While both ministers have denied any wrongdoing, their cases threatened to overshadow a president who ran on a ticket of fighting political sleaze.
Mr Macron has already announced details of his bill to clean up politics, which involves stopping politicians hiring members of their own family, a ban of up to 10 years for MPs and senators convicted of corruption or fraud, and reform of party financing.
The man who presented the proposals is MoDem leader François Bayrou, the justice minister whose party won 42 seats in Sunday's elections in areas that went uncontested by LREM. Mr Macron's party secured a majority in parliament with 308 of the 577 seats.
In a statement, Ms Goulard said that the president's commitment to restoring confidence in public office "must take precedence over any personal considerations". As the inquiry continued, she wanted to be in a position to show her "good faith", she said.
The president's allies have voiced confidence in Mr Bayrou, despite the embarrassment of the fake jobs inquiry. "Mr Bayrou is destined to stay in the government," said Prime Minister Edouard Philippe.
The justice minister refused to comment on Ms Goulard's resignation on Tuesday, describing it as a personal decision. He has also insisted that party workers have never taken on fake jobs as assistants to MoDem MEPs in the European Parliament.
Many saw the president's hand in Ms Goulard's resignation, reports the BBC's Hugh Schofield.
She was one of five women given top jobs in the Macron cabinet last month and accompanied the president on his visit to Mali last month, his first trip outside Europe.
Doubts have also been raised about the future of another MoDem politician, European Affairs Minister Marielle de Sarnez. Like Ms Goulard, she is part of the Paris prosecutor's inquiry.