A US government oversight agency has said White House aide Kellyanne Conway should be fired for engaging in banned political activities while in office.
The Office of Special Counsel said Mrs Conway violated the Hatch Act, which bans federal employees from campaigning for candidates while on the job.
The watchdog cited "numerous occasions" in which she violated the law, calling her a "repeat offender".
The White House dismissed the advice as "deeply flawed" and "unprecedented".
The allegations stem from statements Mrs Conway made on television during the 2017 Alabama special Senate election in which she advocated for and against certain individual candidates.
The president, vice-president and some other high level officials are not bound by the 1939 Hatch Act.
In a statement announcing the recommendation, the independent Office of Special Counsel (OSC) said that her "violations, if left unpunished, would send a message to all federal employees that they need not abide by the Hatch Act's restrictions.
"Her actions thus erode the principal foundation of our democratic system - the rule of law."
Flouting presidential norms once again
The Office of Special Counsel has recommended that White House senior adviser Kellyanne Conway be fired by her supervisor. Given that her supervisor is Donald Trump, however, that outcome appears unlikely in the extreme.
The White House has already issued a statement dismissing the report by Special Counsel Henry Kerner, a Trump appointee, as flawed and unfair - the standard administration response to unwelcome criticism from friend or foe.
The language of the Hatch Act is clear, though. Conway is forbidden from using her official authority to influence campaign politics. The special counsel report details numerous times Ms Conway, identified as a senior White House employee, made disparaging comments about Democratic presidential candidates and boosted Mr Trump's re-election efforts.
Hatch Act restrictions are only as strong as a president chooses to make them, however. This, then, becomes yet another instance where presidential norms and traditions are being side-stepped by the current administration.
That means this episode, while perhaps embarrassing for Conway and Republicans, seems destined to quickly fade from view. Congress could always strengthen the law's enforcement mechanisms, but that would require the kind of bipartisan co-operation that has been in short supply of late.
The agency described one episode in which she appears to shrug off the Hatch Act, saying "if you're trying to silence me through the Hatch Act, it's not going to work," and "let me know when the jail sentence starts".
It is up to President Donald Trump whether or not to heed the recommendation and fire his former 2016 campaign manager.
The White House rushed to defend Mrs Conway, calling the special counsel's actions a violation of Mrs Conway's rights to free speech.
"Others, of all political views, have objected to the OSC's unclear and unevenly applied rules which have a chilling effect on free speech for all federal employees," said deputy White House press secretary Steven Groves in a statement to US media.
"Its decisions seem to be influenced by media pressure and liberal organisations, and perhaps OSC should be mindful of its own mandate to act in a fair, impartial, nonpolitical manner, and not misinterpret or weaponise the Hatch Act."
In a letter, White House legal counsel Pat Cipollone also urged the OSC to "withdraw and retract the report and continue the dialogue with this office that should have taken place and that could have avoided many of the errors in the current draft".
What is the Office of the Special Counsel?
Despite having a similar name, the Office of the Special Counsel is not related to Special Counsel Robert Mueller or his investigation into Russian interference in the 2016 US elections.
The OSC is an independent agency run by Henry Kerner, a lawyer who was nominated for the role by Trump and confirmed by the Senate in 2017.
In his letter to the White House about Mrs Conway, Mr Kerner stressed that Mrs Conway was a repeat offender: "Never has OSC had to issue multiple reports to the president concerning Hatch Act violations by the same individual."
But the agency can only recommend action that the White House can take - it cannot hand out punishments itself.