Chancellor Kwasi Kwarteng attended a private champagne reception hours after delivering his mini-Budget, mixing with hedge fund managers who may have profiteered from the crash, according to a report in the Sunday Times.
The evening gathering on September 23 took place in Chelsea at the home of Andrew Law, a financier and senior party donor where Mr Kwarteng is said to have shared 'insights' over planned expenditure cuts.
Mr Law has an estimated £750million fortune and since 2004 has donated £3.6million to the Tories.
He admitted to shorting the pound in recent years, which has helped him make a profit from the pound's recent decline in value.
The Liberal Democrats called for an inquiry amid questions over Mr Kwarteng's political judgement and whether the event affected his decision to hint at further tax cuts days later.
The pound hit a new low against the US dollar following the mini-Budget, dropping to $1.0327 before recovering to above $1.08.
Guests reportedly drank wine, champagne and cocktails and according to a source in the report the mood was “very, very positive”.
Following the reception, the Chancellor was allegedly dubbed a "useful idiot" by at several prominent hedge fund bosses.
The reception had 30 guests, including stockbroker Howard Shore, Swiss-born London banker Sir Henry Angest, corporate financier Lord Leigh of Hurley and merchant banker and investor Selva Pankaj.
Conservative Party chairman Jake Berry was in attendance as well as William Salomon, a senior partner at Hansa Capital and director of Civitas Investment Management Andrew Dawber.
Representatives from the property, hospitality, healthcare and education sectors were also there as the chancellor was congratulated on the reforms he had made earlier in the day.
One source said he was "high on adrenaline" while two others said he called Friday a “great day for freedom”.
The report said the under-fire Chancellor privately dined with his former boss and hedge fund investor Crispin Odey during the Tory leadership contest.
Mr Odey has since told the Financial Times that bets against UK government bonds were the “gifts that keep on giving.
Tory officials said Mr Kwarteng was at the gathering, which was arranged by the party’s campaign headquarters, for one hour to give a five-minute talk on his Mini-Budget.
Source close to the Chancellor told the Mirror: “Any suggestion attendees had access to privileged information is total nonsense.
"The Growth Plan published on Friday included a commitment to review our Tax Code to make it simpler, better for families and more pro-growth.
"The government’s ambitions on lowering the tax burden are hardly a state secret.”
Liberal Democrat Treasury spokesperson Sarah Olney said: "While struggling homeowners saw their mortgage bills spiral, it seems the chancellor was sipping champagne with hedge fund managers profiting from the falling pound.
"How out of touch can you get. We need an official inquiry into this now."
