Defense Secretary Ben Wallace has sent a resignation letter to Prime Minister Rishi Sunak after four years in office, according to the document published by the UK government on Thursday.
"After much reflection, I have taken the decision to ask that I be allowed to step down. I won my seat in 2005 and after so many years it is time for me to invest in the parts of life that I have neglected, and to explore new opportunities," the letter read.
Sunak, in turn, accepted the resignation, saying that he fully understands his desire "to step down after eight years of exacting ministerial duties."
"You leave office with my thanks and respect," Sunak added.
Maria Zakharova, Russian foreign ministry spokeswoman, reacted to Wallace's resignation in an ironic manner.
"Let's say goodbye to the character responsible for the contamination of Ukrainian lands with radiation through the supply of shells with depleted uranium to the Kyiv regime. Agent 006 ingloriously left the battlefield," she said.
In an interview with a UK newspaper in July, Wallace confirmed he was "not standing next time", saying that he would step down from office in the fall and retire from politics as part of a planned cabinet reshuffle.
Also in July, Wallace, who is notorious for being an ardent supporter of arms supplies to Ukraine, said that the UK had delivered 15 times more artillery shells (over 200,000) to Ukraine than Downing Street had planned a year ago.
The UK, along with its allies, not least the US, ramped up their military assistance to Kiev shortly after Russia launched its special military operation in Ukraine.