Donald Trump stepped up his attacks on the Federal Reserve on Monday, accusing it of bowing to political pressure from the Obama administration by keeping interest rates low and creating a false market in equities with its stimulus policies.

Wading into a period of intensifying market volatility just over a week before the Fed’s next policy meeting, the Republican presidential candidate said Janet Yellen, the Fed chair, was “obviously political and she is doing what Obama wants her to do”. He predicted stocks would slide when the rates finally rose.

“The interest rates are kept down by President Obama,” Mr Trump told CNBC on Monday. “What they are doing is, you know, I believe it is a false market because money is essentially free.”