The Macron camp's buzzword is "hypocrisy".
The French president's partner has duties, an office, bodyguards and other staff, but no official status or specific budget, they point out, arguing that mean a lack of oversight.
"There is transparency on the presidential budget but opacity on the resources allotted to the first lady," said Aurore Bergé, the spokeswoman for the ruling Republic on the Move (LREM) party's group in parliament.
"The idea is that we end this hypocrisy," she told Europe 1 radio.
Asserting that Brigitte Macron receives 200 letters a day, government spokesman Christophe Castaner claimed that giving her an official role would mean oversight of her expenses and he, too, declared "Stop the hypocrisy!"
Macron said he was in favour of creating a first lady's position during this year's presidential campaign and has charged his staff with drawing up proposals, which should be ready in about two weeks' time.
But opposition politicians have laid into the idea of creating an official status for an unelected individual during the ongoing debate on cleaning up French political life.
And an online petition against the idea had attracted 284,784 signatures and a lot of publicity by Tuesday afternoon.
But Castaner said that the presidential spouse would not receive a salary and there would be no change to the constitution, implying that the idea of creating a title of first lady is no longer on the order of the day.
Opponents of the move kept up their offensive on Wednesday.
"I'm against a presidential monarchy!" exclaimed Clémentine Autain, an MP for the hard-left France Unbowed party. "When we elect a president we don't elect a couple. This position of first lady was really a rearguard idea."
"You can't be demanding of MPs and at the same time organise major resources for the head of state's spouse at the republic's expense," Nicolas Bay of the far-right National Front told RFI.