Conservative MPs have said the Chancellor made the remarks at a secret meeting at his Downing Street office, the contents of which have been leaked to The Mail on Sunday.
The disclosure came as Mr Osborne is poised to announce a Budget boost for the low-paid by raising the threshold for income tax to £10,500, while rejecting pleas to stop more middle earners being dragged into the 40p tax band.
MPs at the meeting reacted with horror when Osborne told them: “Let’s not forget there are advantages in more people paying tax at 40p. It means they feel they are a success and joining the aspirational classes.
“That means they are more likely to think like Conservatives and vote Conservative. If they are paying 40p tax they have a greater interest in cutting Government spending because they are paying for it. All the polling evidence suggests I am right.”
One MP who was present told the Mail on Sunday: “There was a stunned silence. I never thought I’d hear a Tory Chancellor say paying more tax is good for the middle classes. It was a Marie Antoinette moment.”
Another added: “The 40p rate may not affect the millionaire son of a baronet like Mr Osborne but it is killing hard-working people who earn around £40,000. It was an insult and shows how out of touch this Government has become.”
One Tory told Osborne that his argument was ‘illogical’: “You cannot argue that making more people pay 40p tax is good because they are more likely to want to cut government spending, while letting more people at the bottom end pay no tax whatsoever.”
The Chancellor’s claim is said to have been made at a meeting with senior Tory MPs on the executive of the party’s 1922 Committee on 5 February.