The Reserve Bank of Australia could lose some control over its ability to set interest rates independently if Donald Trump is successful in his bid to take control of the US central bank, experts warn.

Ten days after the US Department of Justice announced a criminal investigation into the Federal Reserve’s chair, Jerome Powell, the supreme court on Wednesday will hear arguments in a legal case that will determine whether the president has the power to fire Lisa Cook, a member of the Fed’s board of governors.

National Australia Bank’s chief economist, Sally Auld, said if the court upholds Trump’s efforts to sack Cook then that could spell the beginning of the end of the central bank’s independence.

The consequences of Washington DC wresting control over monetary policy could be severe, and ultimately lead to higher inflation.

It would likely trigger a crisis in confidence in the American currency and financial assets, such as stocks and bonds, Auld said, with ramifications for other central banks.

In this worst case scenario, “the magnitude of the depreciation of the US dollar would be quite significant”.

“If the Aussie dollar jumped 15%, that would make our currency expensive and that in itself might be enough to demand the RBA cut rates. Their hand could be forced.”

So far, investors remain untroubled with the unprecedented attack on the Fed, and this calmness in financial markets “feels a little bit out of sync with the way people are sensing the world at the beginning of 2026”, Auld said.

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There are 12 members of the Federal Open Market Committee who have a vote on rate decisions.

They include the seven members of the Washington DC-based board of governors, the president of the Federal Reserve Bank of New York, and four of the remaining 11 presidents of the regional reserve banks (who serve one-year terms on a rotating basis).

The Fed’s next rate decision is due early on 29 January, Australian time, and will be the first made in the shadow of the looming threat of a Department of Justice criminal investigation into Powell.

Even if Trump is unable to gain direct power over the central bank, as is likely, the political pressure and threats have already chipped away at the image of an independent institution.

The chief economist at AMP, Shane Oliver, said a politically controlled Fed could keep rates lower for longer and “end up with an inflation blowout” that could smash the US dollar and drive Wall Street lower.

Like Auld, Oliver believes the “upshot could mean lower rates” in Australia.

“A stronger Aussie dollar and lower interest rates; some Australians would think that’s not a bad outcome. But the risk would ultimately be more inflation.”

Oliver said the prospect remained relatively distant.

“To get to that point you’d need to have Trump gaining complete control over the Fed. If he gets control of four of the seven governors, then he gets some control over who sits as president. That’s when the guardrails around the Fed weaken.”

Successful or not, Oliver said Trump’s push to overturn decades of political support for central bank independence would set a precedent for other populists around the world.

“For Australia, the problem is that this is the world’s most significant central bank. If the threats to independence are happening there, then it would happen here.”

There is already a constituency on the left who would be happy to abandon the principle of central bank independence.

The Greens’ economic spokesperson, Nick McKim, in September last year demanded Jim Chalmers “show some courage” and exercise his legislative powers to “directly override” the RBA and force it to cut rates.

Populist figures on the right, such as rising Liberal figures like Andrew Hastie and Senator Jacinta Nampijinpa Price, may choose to follow Trump’s lead, especially should the RBA raise interest rates this year.

Unions have been deeply critical of the RBA for keeping rates too high at the expense of jobs, but still publicly back its independence.

Oliver said “in some ways [Australia’s institutional settings] are already weaker than the Fed”.

“To get a governor appointed in the US you have to go through a committee, whereas here you are just appointed by the Treasurer.”

Luci Ellis, Westpac’s chief economist and a former senior RBA official, said Australia should still be able to pursue an independent monetary policy even in a world where the American central bank has been suborned by political interests.

“There’s no particular reason we have to follow what the Fed does,” Ellis said, pointing to recent evidence of how the two countries’ monetary policy paths have diverged.

“It would be bad if the biggest and most powerful central bank lost some of its operational independence, but it would not in and of itself change how the RBA would need to behave.”

• Patrick Commins is Guardian Australia’s economics editor