Former prisons minister Ann, 66, gave a talk to the capacity crowd on Sackcloth and Ashes, released in February, which focuses on the history of penance and penitence as well as its importance in modern life.
Ann said: “It is lovely to be in Swindon and be part of the line up.
“Obviously, the festival is getting a good reputation with previous guests singing its praises.
“I have really enjoyed putting this book together as I’m a fiction writer traditionally so this gave me a chance to do something different.
“I wanted this book to be an exploration rather than an explanation.
“One of the joys of reading this book is that the reader can supply their own answers with the information provided.”
The former MP, who retired from politics in 2010, took part in a lively question and answer session at the end of her talk being probed on topics including her writing, political career, religion, the media and of course her appearance on Strictly Come Dancing.
Ann said: “I give these talks all around the country and my favourite part of it has to be the questions “If I could do 55 minutes of taking questions and five minutes of my talk I would, as there’s such a mix of topics.
“Since retiring, I’ve not missed politics at all. I think I left at the right time. I’ve been so busy in my retirement and Strictly Come Dancing has been one of the highlights, I could never have predicted how big it would be for me, it was a great experience which I look back on fondly.”
After the talk, Ann, who partnered Anton du Beke on the BBC dancing show in 2010, signed copies of her new release and previous novels.
Matt Holland, Festival of Literature director, said that he was delighted with Ann’s talk.
He said: “I thought it was really interesting and I think one of the interesting points was when she talked about how people judge others on what you read or hear about them.
“As you don’t necessarily know what to expect with Ann it was a pleasure to welcome such a very nice and approachable human being.
“And I think the audience really enjoyed her talk.
“This is only the second day of the festival but the response so far has been absolutely brilliant.”
The festival, now in its 21st year, kicked off when 300 people went to Lawn Woods for the dawn chorus on Monday.
Highlights of today’s programme include food writer Bee Wilson giving a talk at the Arts Centre at 12.30pm.
The venue will also welcome author and Booker Prize judge John Carey at 6.30pm.
Nigel Jones will be at the Central Library talking about Peace and War: Britain in 1914 at 7.15pm.
Gavin Pretor-Pinney and Tom Hodgkinson will talk about the ukulele at the Arts Centre at 8pm.
The festival runs until May 17. To see the full programme visit www.swindonfestivalofliterature.co.