Chelsea manager Mourinho turned conspiracy theorist by suggesting his side's bid to retain the Premiership is being derailed by officials conforming to an agenda set against the London club.

And, in the wake of Chelsea's frustrating 0-0 draw at Newcastle on Sunday which left the Blues three points behind United, the Portuguese offered what he firmly believes is conclusive evidence that referees are favouring the league leaders.

"The circumstances are difficult for us with the new football rules that we have to face," said Mourinho.

"It is not possible to have a penalty against Manchester United and it is not possible to have a penalty in favour of Chelsea," he added, referring to two contentious decisions within 24 hours which could yet have a significant bearing on the destination of the English game's top prize.

Middlesbrough's Lee Dong-Gook appeared to be fouled by John O'Shea in the final minute of their 1-1 draw with United at Old Trafford on Saturday but a penalty was not awarded.

After eight minutes of Sunday's scrappy stalemate at St James's Park, Mourinho felt Chelsea should have been awarded a spot kick after Salomon Kalou's cross struck the arm of Newcastle defender Stephen Carr. Again, no penalty was forthcoming as referee Mark Halsey waved away sustained claims from the agitated Chelsea players.

"We should have had a penalty, involving Stephen Carr," said Mourinho, who insists he has no fear of being sanctioned over his criticisms. "It was a clear penalty.

"I have the right to speak. I think nobody can punish me because I speak the truth and I am not saying the referees are not honest.

"But on Saturday it was a penalty and today it was a penalty. If somebody wants to punish me for that it means the end of democracy and we go back to old times." Mourinho has never been afraid to speak his mind but the English Football Association will surely come down hard on him after comments which will infuriate and shock in equal measure.

Stopping short of claiming an out-right fix is surely no defence with the implication of unfairness at the root of England's national game bound to bring punishment.

And it is not as if Mourinho made his wild claims knowing he will be long gone this summer. Speaking for the first time since Chelsea's chief executive, Peter Kenyon confirmed there would be no change of management this summer, Mourinho revealed he want to stay.

"I opened my heart and told the board that I wanted to stay," he said. "It feels good and now we are working together for the future."

But what of Chelsea's thinly veiled approach to the former Germany coach Jurgen Klinsmann? "A board is a board and they can do what they want," replied Mourninho. "For a long time I have been telling them I want to stay but they have a right to make their announcement when they want.

"If they had decided they wanted to sack me at the end of the season then that was their right but I am staying and I am looking forward to a fourth season in charge of Chelsea." If Mourinho does stay, he may experience the unfamiliar sensation of kicking off next season without a league title to defend. Chelsea looked tired as they struggled to find any attacking momentum against Newcastle.

While Chelsea had legitimate claims for a penalty when Carr put his arm out to block Kalou's cross, they appear to be paying the price for their strenuous efforts to keep pace with United in recent weeks.

They registered just one shot on target when Didier Drogba headed goalwards but Steve Harper easily saved his effort to put United back in control of the title race.