Tottenham Hotspur Supporters' Trust has called for "emergency action" and for match tickets to be refunded after Spurs' 5-2 loss at Atletico Madrid on Tuesday.
Tottenham boss Igor Tudor is under pressure after becoming the first Spurs boss to lose his first four games in charge of the club.
He is also facing criticism for withdrawing young goalkeeper Antonin Kinsky after just 17 minutes following two errors that led to goals.
Tottenham Hotspur Supporters' Trust called the night "a total disgrace".
"From the January transfer window to the management appointments, the lack of leadership and the total absence of anyone with a Spurs pedigree informing these decisions," read the THST statement.
"Where is the Daring to Do? Where are the Echoes of Glory?
"Emergency action is needed as right now we are sleepwalking off the edge of a cliff.
"Being a Spurs fan has never been so difficult but supporters will not sit by and watch the club continue to decline.
"At the very least those in Madrid should have their match tickets refunded. But all we really care about is that the club make us proud.
"We are here to support the team and be the 12th man. But we all deserve so much more."
Speaking on the No Tippy Tappy Football podcast, former Spurs boss Tim Sherwood said Tudor has been making some confusing decisions.
He explained: "He's gone from three at the back to four at the back, then back to three again, with players playing out of position. I've scratched my head at some of the decisions he's made since he came in.
"He hasn't given the players a lift at all. He's a firefighter who has a can of petrol in his hand at the moment – he's adding fuel to the fire rather than restoring confidence to the players.
"Hopefully he can turn it around but, if he doesn't, I think Spurs might roll the dice again. There's an international break after their game against Nottingham Forest, which would be a good opportunity for a new manager to come in and have a look at things."
