Carl Bernstein has said Donald Trump is “dangerous beyond any modern presidency”, responding to the dismissal of the President’s chief of staff.

Shortly after Reince Priebus was fired from the White House and replaced by former Homeland Security Secretary John Kelly, veteran journalist Bernstein took to Twitter to name what he saw as an even bigger problem.

“The problem is not the chief of staff. The problem – dangerous beyond any modern presidency – is the President,” he wrote.

Mr Bernstein, known for being one of two Washington Post reporters who brought down the Richard Nixon administration after revealing it broke into the Democratic National Committee headquarters in the 1970s, has been a vocal opponent of the President.

He has spoken against Mr Trump’s alleged willingness to work with the Russians during the election campaign and his attempts to block the ensuing investigation, as well as his relentless attacks on former opponent Hillary Clinton and his alleged promotion of his business activities whilst in the White House. Mr Trump has denied colluding with Russia.

Mr Bernstein has also said that the President’s firing of former FBI director James Comey during the Russia investigation in May was a “dangerous” situation and Mr Trump’s attacks on the press were more dangerous than Nixon’s.

Earlier this month he told CNN: “We are in the midst of a malignant presidency. That malignancy is known to the military leaders of the country, it’s known to the Republican leadership in Congress who recognise it, and it’s known to the intelligence community and the presidency of Donald Trump is not functioning.”

Since he gave the interview, former press secretary Sean Spicer stepped down, Mr Priebus was sacked and former communications director Anthony Scaramucci was fired after 10 days in the role.

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Mr Trump tweeted after Mr Scaramucci’s departure: “A great day at the White House!”

In March, two months after the President was inaugurated, Mr Bernstein declared it would be “impossible” for Mr Trump to regain the trust of Americans.

“He is someone who has lied at will all of his adult life. Lying has been a key element of his advance in business,” he told CNN, where he is employed as a political commentator.