In an extraordinary break from the diplomatic restraint typical of central banks, a dozen leaders of the world’s foremost monetary institutions issued a joint statement in January declaring their “full solidarity” with the US Federal Reserve and its embattled chair, Jerome Powell.

“The independence of central banks is a cornerstone of price, financial and economic stability in the interest of the citizens that we serve,” they wrote.

The move was intended to shore up the separation of monetary policy and political interference viewed as crucial to Western economies, a principle which came under unprecedented strain amid bitter public clashes between US President Donald Trump and Powell.

Those tensions escalated into a controversial criminal investigation of Powell by the US Department of Justice over alleged cost overruns during renovation of the Federal Reserve headquarters.

Now, stepping directly into the crossfire is Kevin Warsh, Trump’s pick to succeed Powell, who since his nomination in January has come under increasing scrutiny in US and Chinese economic circles.

Ahead of the expected full Senate confirmation hearing for Warsh next week, two questions have come into sharper focus: can the Fed retain its political autonomy, and will Warsh be able to advance his policy agenda or be overshadowed by Powell’s lingering influence?

Despite Warsh assuring the Senate banking committee during its confirmation hearing on April 21 that “monetary policy independence is essential” and he would “absolutely not” become Trump’s “human sock puppet”, global scepticism endures.