Mims Davies, who was Minister for Civil Society from November last year until July, is to leave parliament after the forthcoming general election.
Davies, who is a single parent, said in a statement yesterday that she had made the "tremendously difficult" decision not to seek re-election as the Conservative MP for Eastleigh.
She said it was "entirely a personal decision and not a political one", adding: "It has become increasingly difficult to juggle the responsibilities I have first and foremost as a mother and, secondly, as an MP and minister.
"My children are based largely back in Sussex, my working week is largely in London or travelling in my role as a minister and my weekends are in Eastleigh – or, more accurately, attempting to look after my daughters and their interests and support my constituents."
Nicky Morgan, the Secretary of State for Digital, Culture, Media and Sport, also announced yesterday that she would leave parliament.
Morgan also held responsibility for charity tax and Gift Aid during her time as a minister in the Treasury from 2013 until she joined David Cameron’s Cabinet as education secretary in 2014.
So whatever the outcome of the election on 12 December, a new person will be in charge of the government department that includes the Office for Civil Society.
Morgan cited personal abuse and the impact on her family as reasons for her decision not to seek to be re-adopted as Loughborough MP.
In a letter to her local Conservative chairman, she said: "I have made the very difficult decision that I can't commit to another five-year term, and now is the time for me to stand aside and be at home far more."
Two other familiar figures in the voluntary sector are also set to leave the House of Commons in December.
Nick Hurd, who was civil society minister from May 2010 until July 2014, announced in September that he would not seek re-election as the Conservative MP for Ruislip, Northwood and Pinner.
Hurd, who has six children and is currently the Minister of State at the Northern Ireland Office and the Minister for London, said in a statement that he originally intended to be an MP for as long as his constituents elected him.
"However, much has changed since then," he added. "Politics is now dominated by the ongoing division over Brexit.
"More happily, my private life has been changed profoundly by the birth of my two youngest children.
"I now feel that it is time for me to make a change and embrace a new challenge."
Roberta Blackman-Woods, who was Labour's shadow minister for civil society from October 2010 to October 2011, revealed in July that she would not seek re-election as MP for City of Durham, "largely for family and personal reasons".
Blackman-Woods intends to return to academia.