Booker Prize has become tougher, more covetable, says author Anuradha Roy

"A bigger field -- virtually everyone writing in English -- makes it a much tougher and more covetable prize than it was when it had only British and Commonwealth writers," Roy explained.

The prize worth £50,000 had in the year 2013 expanded its criteria for eligibility to allow all authors who write fiction in English to enter as long as they are published in the UK. Previously only authors from Britain, Ireland, the Commonwealth and Zimbabwe were eligible. In the past five authors of Indian origin -- V S Naipaul, Salman Rushdie, Arundhati Roy, Kiran Desai and Aravind Adiga have won the Booker.

Meanwhile in Roy's fiction Sleeping on Jupiter, her third novel she details a tale of three feisty old women from Kolkata who embark on a holiday together. The author says the longlist announcement came as a complete surprise. "I didn't expect it at all. It was a complete surprise and it took me a long time to convince myself it had actually happened".

Set in an imaginary pilgrimage sea town called Jurmuli, the fiction also dwells on the subject of violence and child abuse. "This book started as a long short story with three old friends going on a part-pilgrimage, part holiday. I was interested at that time in friendship -- and a lot of this book is about the complexities of friendship," says Roy.

Roy, whose previous novels include An Atlas of Impossible Longing and The Folded Earth says she is not prompted by current social realites to explore themes. "I don't ever choose a theme: it's always character and place-driven for me," says the 48-year-old author.

"I found after finishing the story that I kept thinking about a girl who occurred in it as an incidental character. A temple guide too was in that short story -- again as an incidental character. As I worked more on the two of them the novel took the shape it did," says the author.

In her book Roy details the story of a 25-year-old who returns to Jarmuli after being adopted by a family in Norway who takes her away from India. So why did she pick Norway for her plot? On being asked Roy lists out a couple of reasons.

"At an orphanage I encountered through my mother who worked there, I came across several Scandinavians who had adopted older children or children with special needs. I suppose this was one reason; the second is that it is very far from here in every conceivable way, and I needed that for the novel," says the author

Roy, who won the Picador-Outlook Non-Fiction Prize in 2004 for her essay, Cooking Women also works as a designer at an independent press which she runs with her husband.

Among fellow 12 Booker longlisted authors Roy says she has only read US author Marilynne Robinson and Anne Enright from Ireland. "I've read Robinson before, though not this book. And I've read some Enright. None of the others," says Roy.