Sir Peter Stothard has edited the Times Literary Supplement (TLS) for almost a decade and spent the past seven months reading an "unnatural" 145 books on the search for this year's Man Booker Prize. He has been left hugely critical over the decline in current standards of literary criticism, and says the rise of bloggers will leave the industry "worse off".

The 61-year-old says: "There is a widespread sense in the UK, as well as America, that traditional, confident criticism, based on argument and telling people whether the book is any good, is in decline. Quite unnecessarily."

"Criticism needs confidence in the face of extraordinary external competition," the former editor of The Times says. "It is wonderful that there are so many blogs and websites devoted to books, but to be a critic is to be importantly different than those sharing their own taste… Not everyone's opinion is worth the same."

The rise of blogging has proved particularly worrying, he says. "Eventually that will be to the detriment of literature. It will be bad for readers; as much as one would like to think that many bloggers opinions are as good as others. It just ain't so. People will be encouraged to buy and read books that are no good, the good will be overwhelmed, and we'll be worse off. There are some important issues here."

He has announced the six novels to compete for the £50,000 Man Booker Prize in a year he believes has been "strongest for a decade". He chaired the judges and made sure each of his colleagues had read all those in the initial running in what proved a gruelling process.

"It was hard work. In a normal year, you might read 20 novels. So to read 145 in seven months is an unnatural act," he says. "But it's an important unnatural act because in a way literary criticism is an unnatural act. It is work, a technique, a skill."

Sir Peter, who is currently re-reading the shortlisted novels to help arrive at a winner, surrounds himself with literature often to the detriment of other forms of entertainment. He cannot remember the last sporting event he went to and has no interest in films, admitting to only ever seeing six films in his lifetime.

Long bookcases line his study while first edition manuscripts sit in glass cases alongside. He has written two books, and is finishing a third. He is also surrounded by writers in his personal life, married to novelist and travel writer Sally Emerson. Their daughter, Anna Stothard, was nominated for the longlist of this year's Orange Prize for her second book, The Pink Hotel.

The shortlist saw celebrated novelists Hilary Mantel and Will Self in contention, alongside less well known authors including Deborah Levy and Tan Twan Eng. "What made it really worthwhile was finding we had half a dozen extraordinary and exhilarating pieces of prose," Sir Peter says.

The shortlist is rounded out by first-time writers Jeet Thayil and Alison Moore. "Some of the prose in the novels actually glows. Every one of those writers is a master of a certain technique, even those writing for the first time," he says.

A row broke out in 2011 over a perceived dumbing down of the prize as the chair of the judges Stella Rimington said she wanted books "people would read and enjoy".

He dismisses the readability tag as a "side issue" on judging novels and concedes the organisers may have chosen him as chair of the judges to avoid similar issues this year. "The novel is more than a story. Storytelling is a great art and not to be knocked."

"Yet, If the English novel does nothing to renew the English language, then it really doesn't do anything. The great works of art have to renew the language in which they're written. They have to offer a degree of resistance."

His own connection with artistic criticism and newspapers came at a young age. At just 15, he won a competition to be the Daily Telegraph's young jazz critic, although he adds: "It probably wasn't the most competitive category."

He studied classics, which has remained a lifelong passion, at Trinity College, Oxford where he also edited the Cherwell student newspaper.

After leaving, he worked a series of different jobs, he joined The Sunday Times in 1978. There he found an industry in transition. Newspapers were modernising, a process that would culminate with The Times and The Sunday Times moving to Wapping.

He moved to The Times three years later, and following stints as chief leader writer, deputy editor and chief of the Washington bureau, he was appointed editor in 1992. "It was a very competitive period for the newspaper industry, it was a vigorous commercial battle."

This year, a bruising one for journalism for different reasons, he hopes newspapers can band together "in the face of technical change and political risk for their future". He is extremely concerned about the outcome of the Leveson Inquiry. "The press has a lot of enemies. I hope it's not too late; I would like to see the press as a whole challenge what it looks like the outcome of Leveson is going to be. Unless the virtues of newspaper culture are explained, and only the newspapers will do that, there could be serious dangers down the road."