A new north-south divide has emerged between those who regard Richard Madeley and Judy Finnegan as arbiters of literary distinction and those who, to put it politely, do not.

The celebrity couple became the kingmakers of fiction in 2004 when they began the Richard & Judy Book Club on Channel 4. Their recommendations increased sales of some titles by up to 800 per cent. However, research by librarians shows that their power to influence readers is strictly regional.

Lending figures for last year suggest that southerners are slaves to Richard & Judy, flocking to their local library to borrow everything they mention. The couple’s recommended titles make up at least half of the ten most-borrowed books in London, the South East, the South West, the East, the East Midlands and the South West.

Northerners, by contrast, pay no attention to them. None of the couple’s recommendations appears in the top ten lists for the North East, the North West and Merseyside, Northern Ireland, Scotland or Wales. Readers were much more likely to plump for tried-and-tested books in the crime and romance genres. James Patterson’s hard-boiled thrillers are overwhelmingly popular in the North. Readers in the North East are most likely to select a pulse-quickening romance by Danielle Steel or Josephine Cox.

The only area not following the north-south trend was Yorkshire and Humberside, where eight out of the ten most-borrowed books had appeared on the television show. The West Midlands hovered in between, with two recommended titles.

The reason for the divide is open to speculation, but authors suggested that word-of-mouth recommendations for Richard & Judy books were more likely to become epidemics in the South, where book discussion groups are more popular.

Ian Rankin, whose crime thriller The Naming of the Dead led the borrowing chart in his native Scotland, said: “It could just be that I have not got into book groups in the way that other people have. My wife is in three book groups here in Edinburgh, but she is probably a bit of an anomaly.”

The books recommended by Richard & Judy are often highbrow, and would struggle to generate word-of-mouth buzz without book groups to help them, he said. “One year they chose David Mitchell’s Cloud Atlas. It’s not an easy book to read. I look at the books my wife reads for her book group and think, ‘I wouldn’t read that for pleasure’.”

Stuart Maconie, a Lancastrian author and broadcaster, speculated that Northerners were conforming to class stereotypes. “There might be a certain kind of post-Joanna Trollope novel — involving mild infidelity and empty nest mothers — that appeals to Southerners more than it does to Northerners,” he said. “If you’re living on a council estate in Goole, these kind of Canterbury vicar’s wife’s stories don’t appeal. I won’t hear a word against Richard and Judy — I think they are the greatest arbiters of literary taste since F. R. Leavis — but I wonder if the fiction they recommend is about a certain type of person.”

The power exercised by Richard and Judy is on the wane, however. During their heyday on Channel 4 they commanded the attention of 3 million viewers, but their move last year to Watch, a non-terrestrial channel, has reduced their audience to as little as 12,000 — fewer than a programme about train journeys in Switzerland.

Books featured in the latest programme each sold an average of 8,000 copies in the first week — a respectable figure, but a sharp drop from the last two series on Channel 4, when the average was more than 11,000.

The most startling weekly sales increase was for David Nicholls’s Starter for Ten in 2004, which received a sales boost of 871 per cent the week after it was mentioned. The book has since been turned into a film starring James McAvoy.

The library lists — compiled by the Public Lending Right, which rewards authors with six pence for each loan of a book — show that regions responded differently to each book. London, the South East, the South West and the East Midlands rushed to take out Kate Morton’s The House at Riverton, but the East preferred Simon Kernick’s Relentless.

Northerners and Southerners are undivided on one issue: neither can resist books about a certain teenage wizard. Harry Potter and the Deathly Hallows, the final volume in J. K. Rowling’s phenomenally successful series, was in the top five in every British region.

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