Mark Lancaster said "all good things come to an end" as he announced he was stepping down (Picture: Mark Lancaster).
Defence minister Mark Lancaster is to stand down at the General Election, following "two threats" on his life.
Mr Lancaster has served as the Conservative MP for Milton Keynes North since 2005 and entered the Ministry of Defence in June 2017.
He said the "anger" and "abuse" in modern-day politics is "not the politics we want or need for our great country".
"We have always been at our best and delivered the most, when we are able to express political disagreements through healthy debate then unite as a community and as a country," he said.
"I hope one day that we can return to such a place."
Making the announcement on his website, Mr Lancaster said: "This has not been an easy decision, but all good things come to an end."
He described his time as an MP as the "greatest honour of my life" but said "now is the right time to seek new challenges".
Former Defence Secretary Sir Michael Fallon said it was a "loss".
"He is a reservist, he plays a role in the Army," he remarked.
"It is a loss to Parliament that people in their forties and even early-fifties are packing it in just as they've accumulated the kind of experience you need as a minister in a very big department like defence," added Sir Michael Fallon.
Mr Lancaster is also a Colonel in the Army Reserves, completing operational tours in Kosovo, Bosnia and Afghanistan.
During his time as an MP, he consistently voted for the use of British military combat operations overseas, according to voting records website, TheyWorkForYou.com.
He was also in favour of replacing the UK's Trident nuclear deterrent programme.
The Army reservist was the only defence minister to retain his position in the Ministry of Defence following the arrival of Boris Johnson at Number 10 earlier this year.
More than 50 MPs, including the Speaker John Bercow MP, have announced they are standing down ahead of the General Election on 12 December.