Johnny Mercer has announced his resignation as veterans minister, according to Number 10.
The Plymouth MP was reported to be unhappy about a lack of progress in dealing with former personnel being investigated for killings during the Troubles in Northern Ireland.
He has been heavily involved in the Overseas Operations (Service Personnel and Veterans) Bill, which is going through its final stages in Parliament.
A Number 10 spokesperson said: “This evening the prime minister has accepted the resignation of Johnny Mercer as Minister for Defence People and Veterans.
“He thanks Johnny Mercer for his service as a government minister since 2019.”
Mr Mercer released his resignation letter to Boris Johnson on Twitter saying “he fought and bled” alongside veterans.
In the letter he wrote: “It is with a heavy heart that I am forced to offer you my resignation from government.
He added: “I remain genuinely appalled by the experiences of some of the nation’s finest people who have served in the Armed Forces.
“I fought and bled alongside them. I’ve been far more fortunate than many of them since and I have a duty to tell their truth to power.”
He said that many veterans have been sectioned or drunk themselves to death because the government cannot find a political solution to “the appalling injustices” they faced.