Jose Mourinho
Jose Mourinho has led Chelsea's frustrations to a series of decisions that have gone against them this season Getty

Chelsea have launched a scathing and unprecedented attack on Premier League referees after publishing a story on the club's official website outlining the lack of penalties they have been awarded this season.

The league leaders have been awarded just two domestic spot kicks this season, the second joint-lowest in the division, and have sought to highlight what they perceive to be an injustice with an online article that identified key individual errors made by referees.

According to the Stamford Bridge club they have been denied nine penalties by officials this season, seven in the Premier League, mistakes that have contributed to an "abnormally low" amount of spot kicks awarded to them this term.

The editorial follows manager Jose Mourinho bemoaning a string of refereeing decisions, particularly after the draw Southampton that saw Branislav Ivanovic's fall in the box overlooked, while the visitors were awarded a spot kick after Nemanja Matic's foul on Sadio Mane.

"I'm happy with the situation. I'm happy with the six-point lead, but I'm not happy with the result," Mourinho said. "If you remember our two matches against Southampton: in one game, one penalty that is not a penalty and in another game a penalty that was not given. You are speaking about six points transformed into two points.

"My opinion is not important. Important is [referee] Mr Mike Dean. His decision was a penalty and his decision was no penalty on Ivanovic."

Though Chelsea are highly unlikely to be reprimanded by the Football Association for the article, it is the second time in less than a week they have used their digital channels to defend themselves.

For those with short memories...

A photo posted by Chelsea FC - Official (@chelseafc) on

In the wake of Chelsea's players confronting referee Bjorn Kuipers in the Champions League prior to the dismissal of PSG striker Zlatan Ibrahimovic, the club's Instagram account responded by posting two images that included Graeme Souness and Jamie Carragher – the Sky Sports punditry duo who have been accused of being heavily criticised by Mourinho.

The attack has been followed by the FA reporting the rise in the confronting of referees this season has been "scary", with chairman Greg Dyke confirming each club in the top five divisions has been reminded of their responsibilities.