Sterling hit 1.32 against the US dollar for the first time since September, after the President's communications director Anthony Scaramucci was fired just 10 days in the job.
The US currency has been sliding in recent months as Mr Trump's faces increased difficulties in pushing his plans through Government.
The president was dealt a major blow when his healthcare plans failed.
There are also concerns the US economy could be slowing, which is keeping pressure on the US dollar.
As well as 10-month lows against the pound, the dollar is sitting at the lowest levels against the euro in around two years.
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Chris Beauchamp, chief market analyst at IG, said: "The longer this US dollar slump goes on, the more worrying it becomes."
Markets now have lower expectations that America's central the US Federal Reserve will raise interest rates again this year, which is also keeping the dollar weak.
It comes amid slower growth and lower inflation.
Chair of the Fed Janet Yellen sounded cautious in the most recent update, which helped push a sell-off in the US dollar.
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Trump's press secretary REVEALS truth behind Scaramucci departure
FXTM Chief Market Strategist Hussein Sayed: "Six months into Trump's presidency has already passed without any significant legislative achievement and not even the ‘skinny repeal’ of Obamacare.
"Investors are apparently growing more concerned that his administration will not be able to agree on the rest of his agenda which is a clear sign that markets have lost the claimed confidence.
"Although the US GDP growth more than doubled in Q2 compared to Q1, the 2.6 per cent expansion could not support the dollar as it came slightly short of expectations.
"The Federal reserve also acknowledged that the balance sheet normalisation would begin relatively soon, and one more rate hike still on the table this year.
"Still the USD continued to slide as investors remained skeptical of another rate hike in 2017 with CME’s Fedwatch indicating only a 46.8 per cent chance of a rate hike in December."
More to follow...