The wife of a minister forced to resign for sexting two female constituents has been selected as the Conservative candidate in her husband’s former seat after pledging to support victims of domestic abuse.

Kate Griffiths, whose estranged husband, Andrew Griffiths, resigned from the government for sending 2,000 sexually explicit messages to two women, was chosen as the party’s candidate for the seat of Burton in a shock move on Tuesday night.

Griffiths had announced at 7pm he was stepping down from frontline politics and instead backed his wife to replace him in the East Staffordshire seat, saying she would make a remarkable member of parliament.

On Monday night, a majority of members refused to back the disgraced former minister, who was previously chief of staff to Theresa May, meaning the field was opened to other candidates.

In a statement, Griffiths said she left her husband “on the day that he told me about the behaviour that was published in the press. Our relationship ended on that day and the divorce is being finalised. I am not able to say more about this now as legal proceedings are ongoing but I want to make it clear that I have not sought, nor do I accept, Andrew’s offer of political support.”

She said the last 18 months had been “the most difficult of my life” and that, having become a single mother, she had “found a strength and resilience which I didn’t know I had”.

Griffiths said her “first priority” would be to support Boris Johnson and deliver Brexit, and that she would also be a “strong voice for abuse survivors”.

She added: “I am not a professional politician but sometimes in life you have an opportunity to do something good for your community and I [am] determined to make a real difference for the area that I love.”

A copy of Griffiths’ candidate CV, which has been seen by the Guardian, sets out her wide range of priorities including on Brexit, the NHS and crime, as well as local issues.

It begins: “I am a hardworking, dedicated, Burton-born lifelong Conservative and I want to be able to make a difference to people’s lives. In this social media age of online abuse towards female MPs I think it’s more important than ever that we have women in parliament to create a balance that better represents the makeup of our country.”

Griffiths goes on to discuss the effect on her of the sexting scandal that prompted the downfall of her estranged husband last November.

She writes: “In the past 18 months I have found strength and resilience which I didn’t know I had, borne out of self-respect, dignity and the fierce desire to protect my daughter.”

She adds: “As a former MP’s wife I have the experience and knowledge of the commitments and demands of the job that I am seeking to do, and I am going into this with my eyes open.”

Griffiths had the Tory whip removed in July last year and resigned as minister for small business after it emerged he had sent explicit messages to two women. He had the whip reinstated in December last year.

This year, he was cleared of wrongdoing in the sexting case by the parliamentary standards watchdog, which said it had not found evidence that the MP sent the messages while engaged in parliamentary activities or had breached the Commons code of conduct.

Griffiths said he was “deeply ashamed” of the scandal when it emerged and later said that at the time of sending the messages he was suffering from mental health problems linked to having been sexually abused as a child.

“I am sorry that my mental health breakdown last year had such a profound impact on my family and the lives of those around me,” he said on Tuesday. “It was my life’s ambition to be an MP and it truly is the greatest privilege that anyone can have. However, I have sadly come to the decision that it is time for me to leave frontline politics.”

The Conservatives are defending a majority of more than 10,000 in the constituency, where a majority of local party members refused to back the incumbent MP for reselection.

One party member present said the room was “stunned” when Kate Griffiths announced her candidacy on Tuesday night, when it emerged that her husband had withdrawn.

The party member said Andrew Griffiths had given a 30-minute speech followed by about a dozen questions on Monday night before a 50/50 split vote on whether to reselect him. The field was opened to other candidates on Tuesday night.

“A lot of people clearly are just thrilled that he’s gone,” said the party member. “These people will be very sympathetic to Kate because of what she’s gone through. There will be a swing to her and the party will throw everything behind her as well.”