Supreme Court Justice Ruth Bader Ginsburg has responded to Donald Trump's call for the top US court to stop impeachment.
"The president is not a lawyer," she told the BBC in an exclusive interview, adding: "He's not law trained."
In a wide-ranging conversation, she also said poor women were victims of restrictive abortion access.
The US president is expected to be impeached by the House of Representatives on Wednesday.
The House, controlled by the Democrats, accuses him of an abuse of power in his dealings with Ukraine.
Impeachment is like an indictment – the charges will then be sent to the Republican-controlled Senate for a trial, where senators act like jurors.
President Trump is expected to be acquitted there of the two charges he faces.
What did Ms Ginsburg say about impeachment?
Earlier this month, the president suggested in a tweet that the Supreme Court could step in.
"Radical Left has NO CASE. Read the Transcripts. Shouldn't even be allowed. Can we go to Supreme Court to stop?"
When the BBC's Razia Iqbal asked the justice what her reading of the constitution was in this context, she replied: "The president is not a lawyer, he's not law trained."
Ms Ginsburg also implied that senators who display bias should be disqualified from acting as jurors in the trial.
There was criticism over the weekend of Mitch McConnell, who leads the Republican party in the Senate, for saying an acquittal was a foregone conclusion.
When asked about senators making up their minds before the trial, the Supreme Court Justice said: "Well if a judge said that, a judge would be disqualified from sitting on the case."
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What did she say about abortion access?
"I think society needs to be more active on this issue," she said.
"And the truth is that with all these restrictive laws, the only people who are being restricted are poor women."
Women with the means to travel to other states to get abortions were able to, she added.
Poor women bear the brunt of states' laws that restrict access, she said.
"They normally can't pay a plane fare or the bus fare, they can't afford to take days off of work to go."
Why is Ruth Bader Ginsburg important?
President Trump has appoiRead More – Source