WASHINGTON — Britain's uncertain economic and political outlook, caused by Brexit, is reminiscent of its most celebrated statesmen — who flirted with financial and political ruin.

In "No More Champagne: Churchill and His Money," David Lough explains how Winston Churchill projected a seemingly extravagant image of wealth despite living on the edge of crippling financial debt.

"He was a very high-risk operator both in his personal finances and in his politics," Lough told CNBC. "And what was most surprising was the extent of his gambling and his continuous search for excitement and taking risks. He didn't listen to advisers on money and he didn't listen to advisers on politics."

Lough, a retired banker who spent four years researching Churchill's finances, said the "British Bulldog" accumulated a debt equivalent to $4 million in today's dollars by the 1930s.

"I think bankers basically believed in him," Lough explained, adding that Churchill kept a good relationship with lenders while avoiding to pay his debts.

In 1925, Churchill took out an emergency bank loan, bringing his borrowings to £30,000 or $2.1 million at current exchange rates and adjusting for inflation (inflation multiples: UK£ x 50). The following summer, he made several budget cuts to Chartwell, his country estate.

"Nothing expensive is to be bought, by either of us, without talking it over," Churchill wrote to his wife Clementine, according to Lough.

"No more champagne is to be bought. Unless special directions are given only white or red wine, or whisky and soda will be offered at luncheon, or dinner. The Wine Book to be shown to me every week. No more port is to be opened without special instructions."

"Cigars must be reduced to four a day. None should be put on the table; but only produced out of my case."