News International (NI)'s decision to reduce retailers' cash margin on The Sun by 1.16p per copy has been met with "revulsion and contempt" by newsagents, who say the move will take about £10m a year out of retailers' tills.

NI announced earlier this month that retailers in England, Wales and Northern Ireland have been receiving a share of cover price of the Monday to Friday editions based on the full price of 35p, although The Sun has sold on a price promotion of 30p since July 2008.

In a strongly worded response, the National Federation of Retail Newsagents accused NI of having "a knife poised to stab retailers in the back" and cancelled the publisher's sponsorship of its annual trade show, a partnership announced just days earlier.

Head of News and Magazines Stefan Wojciechowski said: "How NI thinks that it is going to win the hearts and minds of independent retailers by treating them this way is beyond comprehension. If they think retailers are just going to allow this to happen, and encourage other publishers to follow suit, then they may have miscalculated badly."