Tottenham head coach Jose Mourinho believes VAR is "killing the best league in the world" as Spurs appeal Son Heung-min's red card in the Premier League defeat to rivals Chelsea.

Son was sent off for kicking out at Chelsea defender Antonio Rudiger during Tottenham's 2-0 London derby loss to Frank Lampard's Blues on Sunday.

The 62nd-minute dismissal followed a VAR intervention due to Son's reaction in retaliation to a challenge by Rudiger – referee Anthony Taylor initially seeing no offence before he was overruled by video assistant referee Paul Tierney.

"The situation with Son, I think Mr Tierney got it wrong. It's the wrong call," Mourinho said. "This is England, the Premier League, the best competition in the world, with characteristics that if we change them we are killing the best league in the world.

"Paul Tierney decides yes and Anthony Taylor, in real time, five metres from the situation, decided no [red card]. So who was refereeing the game? Not Mr Taylor. It was Mr Tierney.

"VAR was supposed to support football, to bring truth to the spectacle. They did that with the penalty decision and they killed the game with Son's decision."

The result left Tottenham in seventh position, six points adrift of Chelsea – who occupy the fourth and final Champions League place.

Mourinho has lost three matches since replacing Mauricio Pochettino – two Premier League defeats and a Champions League loss – as Spurs continue to ship goals.

Tottenham have only kept two clean sheets in 18 Premier League matches this term, with one of those coming in Mourinho's six league games.

"I know how to fix it. But to do it 100 per cent I'm going to take away from the team some qualities that we want to keep," the former Manchester United boss added.

"It is not difficult to put all the focus on a clean sheet, on improving defensive organisation and trying to kill mistakes. But with the players we have, and their habit, the difficult thing is to to put it right defensively without losing the qualities that we can have offensively. So we need time."