Marks & Spencer executive chairman Sir Stuart Rose has criticised Prime Minister Gordon Brown’s unhelpful attitude towards business leaders who lent their support to the Conservative Party’s position on National Insurance.

Rose was among 68 directors – including other retailers such as Next chief executive Simon Wolfson and Kingfisher boss Ian Cheshire – who have so far come out in opposition to Labour’s proposed increase in National Insurance, which they argue is a tax on jobs, and supported Tory plans for a curb.

Top Labour politicians, most recently Brown, have claimed the business people were “deceived”, sparking an angry reponse.

Speaking on Radio 4’s Today programme this morning, Rose said Brown had insulted the business leaders’ intelligence and he returned to the issue in a conference call about M&S’s fourth quarter results.

Rose said: “It’s not helpful to dismiss 60 business people as dupes. To mislead 60 people is difficult.”

He said that he had consistently argued against a NI rise and urged the Government to “cut waste” to save money, in the same way as business such as M&S have.

He distanced himself from party politics however, and said: “I’ve made it very clear that I’ve aligned myself with the Tories on this one issue.”