Spurs were top of the Premier League table before the festive period, but have rapidly languished to eighth following a bad run of form.
The North Londoners have lost five of their last nine games, including three in a row for the first time since 2012.
In the wake of a 1-0 defeat against rivals Chelsea in the Premier League on Thursday night, Mourinho’s men currently sit eighth on the league log, seven points behind fourth-placed Liverpool and 14 points behind leaders Manchester City.
In his latest column on Sky Sports, Merson questioned the tactics deployed by the former Manchester United manager and ascertain Mourinho’s chances of turning things around at the Tottenham Hotspur Stadium.
“Some Tottenham fans will see this, while some might think I'm being harsh, but Tottenham are the worst team in the Premier League to watch, at the moment,” he wrote.
“Sheffield United are bottom of the league and have only won two matches, but they went to Manchester the other week and didn't do what Tottenham did at home, and Sheffield United have got nowhere near the talent Spurs have got.
“Fulham haven't got the talent but at least they tried to have a go at Leicester.
“Thursday evening's game, the first half, for a Tottenham fan was embarrassing. It was embarrassing at the highest level.
“I sat and watched, and I could not believe what I was watching. It is mind-blowing what Jose Mourinho must be saying to those players.
“Poor Carlos Vinicius up front. He's playing up front on his own 20 yards away from every other player.
“They are playing against Chelsea and although Thomas Tuchel has turned things around, it's not a free-flowing football team. It's not a team that's going to score six or seven goals against you. Timo Werner is a good player, who hasn't got going yet.
“Spurs are playing against a centre-forward in Werner who has got one goal against Morecambe in his last 18 games in all competitions and they are still sitting 10-men behind the ball.
“You'd have thought Spurs were playing against Brazil or playing in the second leg of a European tie against the top Barcelona side of old. You've won the first leg 1-0 away from home and you've just got to come back and make sure you get a 0-0.”
