Dorries was born as Nadine Vanessa Bargery in Liverpool. Her father was a bus driver who became a lift operator having suffered from Raynaud's disease, which had necessitated the amputation of his toes. Her father was a Roman Catholic of Irish descent, while her mother was an English Protestant. Dorries was raised as a Protestant.

In 2009, she gave this account of her 2005 selection: "Three weeks before the 2005 general election I, a council estate Scouser, was selected as the Conservative candidate to represent a southern rural constituency. Because the vacancy occurred so quickly and so close to D-day, the party provided my association with a shortlist of seventeen candidates, of which about five were women. Following a long day of interviews in hot sunny rooms, the list was whittled down to a shortlist of three ... I was informed that I had been selected outright on the first ballot ... That pride, that sense of achievement, the knowledge that I was selected on the basis of my performance and merit above all other candidates on that day is what enables me to hold my head up high in this place." Dorries's account of her own selection appears to contradict a news report which The Times ran at the time, reporting that Conservative Campaign Headquarters placed a majority of women on the shortlist and pressed for the selection of a female candidate: "Mrs Dorries, who has three teenage children, easily beat her 11 rivals and won the plum safe seat on the first ballot at the selection this weekend. Party officials were thrilled that the seat has gone to a woman. Previously, only two women had been selected in the 17 safe seats where sitting MPs have retired. Senior party figures had made clear to local dignitaries that they would like the seat to go to a woman and presented the constituency with a shortlist of seven women and five men to underline the point." In a debate on Woman's Hour, broadcast on 22 August 2001, Dorries (as Nadine Bargery) had advocated all-women shortlists if the behaviour of Conservative selection committees did not change. In 2009 though, Dorries was highly critical of David Cameron's proposal to consider using all-women shortlists, arguing against a move which would create "two classes of MPs". She wrote that "Sometimes I feel sorry for some of the Labour women who were selected via all-women shortlists. Everyone knows who they are. They are constantly derided."

Are there any other interesting aspects about this article?
In 2009 though, Dorries was highly critical of David Cameron's proposal to consider using all-women shortlists, arguing against a move which would create "two classes of MPs".