The Independent Press Standards Organisation (IPSO) ruled that a front page story in The Sun, which alleged that Labour leader Jeremy Corbyn only joined the Privy Council in return for a state payout for his party, was inaccurate.
The Sun ran a story on 15 September under the headline: "Labour hypocrite: Leftie who hates the Royals WILL kiss Queen’s hand to grab £6.2m" in which it said Corbyn had joined the Privy Council but falsely alleged that his motive for doing so was to secure £6.2 million in state funding for the Labour Party.
The complaint was made by Rosie Brockhurst, a former journalist who has also previously worked in the Labour Party press office.
IPSO replaces the former Press Complaints Commission and was created 15 months ago following the Leveson enquiry into press standards.
Meanwhile, the Information Commissioners Office has fined the Daily Telegraph £30,000 after it sent thousands of emails to readers on the day of the general election urging them to vote Conservative.
The ICO ruled that Telegraph Media Group broke direct marketing rules because none of its subscribers had given specific consent to receive that type of marketing.