The famed comedian and actor, who occasionally offers punditry on UK politics and media, surfaced on social media to lambast broadsheet editors for a move which saw them contact hundreds of thousands of people to call on them to back David Cameron in May's general election.
Data protection watchdog the Information Commissioner’s Office found on Monday that the newspaper’s parent company, 'Telegraph Media Group', breached direct marketing rules by issuing its digital rallying call.
It said subscribers to the paper's electronic services might have signed up to receive a daily email, but promoting the Tory election campaign had “crossed a line”.
“People may well perceive the paper’s editorial content to have a political bias," said Steve Eckersley, head of enforcement at the ICO.
"But when the Telegraph emailed people directly calling them to vote for a political party they crossed a line,”
It fined the paper £30,000 as a result - but Cleese was quick to pile in with his own scathing critique.
"Daily Telegraph is fined £30,000 for sending emails to its readers saying "Vote Tory". Isn't that what a propaganda sheet is SUPPOSED to do ?" he wrote.
He went on to chastise the broadsheet for not being informed, balanced or accurate - adding that it was not a "proper newspaper".
Cleese then took aim at the Telegraph's owners, the Barclay brothers, suggesting that the reason "all its best writers have left" was down to staffs' poor salaries, which he claimed came at the expense of advertising revenue boosts.
A spokeswoman for TMG defended their original email, saying that while the company was “disappointed” at news of a fine, the response to the email had been “overwhelmingly positive”.
“Although we are disappointed with this ruling, we note the mitigating factors that the ICO highlights in its report," she told the Guardian.
“The response to the email was overwhelmingly positive, and the ICO agreed in its ruling that it was unlikely to cause distress.
"The ruling also recognises that we fully co-operated with the ICO and that we have taken steps to make sure this should not happen again."