British Chancellor of the Exchequer Philip Hammond resigned on Wednesday, a day after Boris Johnson won the leadership race and is prepared to become the new prime minister. 

Hammond said the new leader should choose someone "fully aligned with his policy position."

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Hammond, who is vehemently opposed to a no-deal Brexit that Johnson has not ruled out, also said in a letter to outgoing Prime Minister Theresa May that the unresolved issue of Brexit had caused "uncertainty" for the economy. "My successor should choose wisely on spending pledges and cutting taxes," he added.

"It has been a privilege to serve as your Chancellor for just over three years since you assumed office in July 2016," he wrote in the letter.

"Despite the uncertainty created by the unresolved issue of Brexit, we have been able to make notable progress in rebuilding the public finances and preparing the British economy for the opportunities ahead." 

Hammond continued: "We have made a huge commitment to investment in Britain's infrastructure, housing, Research and Development and technical education – all vital building blocks to overcome the low productivity that has plagued the UK, depressing wages and living standards.

"Public sector net investment is forecast to reach levels not sustained for 40 years from next year, and I am pleased to say that real wages are now growing robustly and are forecast to continue doing so for the remainder of the five-year forecast period.

"We can be proud of these achievements in difficult circumstances - and proud, too, of Britain's continued status as a global financial services hub, a magnet for high-growth technology businesses in Europe, and home to some of the world's best companies."

The 63-year-old Oxford University graduate is one of Britain's most respected officials among European leaders and a champion of London's strategically vital financial hub.

Former London mayor Johnson was sworn into office Wednesday after pledging not to seek any further Brexit extensions, "do or die, come what may."

But Hammond – nicknamed "Spreadsheet Phil" for his dogged devotion to strict budgets – has been that nagging voice who has kept telling Johnson that his promises of a bright no-deal Brexit future are misguided and dangerous.

"I will do everything I can from the backbench to ensure that parliament blocks a no-deal," Hammond said a few days before he formally quit.

(With input from AFP)