Bestselling author Philip Pullman has criticised the "measly, miserly" attitude of some publishers when entering into new contracts with writers.

The His Dark Materials trilogy author, who lives in Cumnor, said writers must be offered a fair percentage of royalties on their works, particularly electronic publications.

It comes as national organisation the Society of Authors called for “serious” changes to be made by publishers or the professional author “will become an endangered species”, following a survey showing that the average income of British authors has fallen to just £11,000.

Mr Pullman, who is president of the Society, said: "Authors are certainly less well off than they were. Thirty years ago you could make an honest living if you wrote steadily and well, for an audience that was solid. You can't anymore.

"The people who are currently making a lot of money are the people that don't actually create the stuff. Without us, whether we're writing novels or picture books, recipe books or travel books, we are the people that create the work that makes them money. And we are being ripped off."

Mr Pullman cited the loss of the Net Book Agreement - set prices for new books with a fixed royalty for the author - along with online bookselling "at enormously reduced prices" and the "reckless" closure of public libraries as key issues bringing down authors' income.

He added: "Weare not against ebooks, but what we are asking for is a proper return.

"Physical books mean you pay for printing and distribution and design, which costs money, and we understand that we can't get more than 10 per cent for it.

"But when you publish an ebook all you have to do is press a button, and actually, we really demand and deserve a 50 per cent royalty. We need to be rewarded properly instead of the measly, miserly way we are now."