The pressure is on Spurs to re-establish their four-point lead over Arsenal ahead of next Sunday's north London derby at White Hart Lane.
Last season Tottenham held a 10-point advantage over the Gunners in February, but they then fell away spectacularly and ended up missing out on Champions League qualification thanks to Chelsea's win in Munich. Andre Villas-Boas is determined not to let the same thing happen again this term. His team have been the personification of consistency in the league, where they are unbeaten since December 9.
They also go in to the game on the back of a morale-boosting win over Lyon in the Europa League - and the man who secured their progression to the last 16 on Thursday night thinks he and his team-mates are playing at the top of their game right now.
"We don't have to fear any team," said Dembele, who secured a 3-2 aggregate win with a 90th minute equaliser in the Stade de Gerland.
"People have respect for us. If you're in a winning mood it's important in the league. We have two more very important games coming up in the league so the confidence will stay high and that's good for us."
Given the gulf in ability between the two sides, West Ham are expected to approach the derby cautiously.
Tottenham have struggled at times to break down teams who shut up shop. They have often had to rely on the brilliance of Gareth Bale to find come away with three points, but Dembele is confident Spurs will be able to overcome their rivals on Monday regardless of the tactics they employ.
"It will be a different game to the Lyon one of course," Dembele said.
"Teams always have a lot of respect for us and they drop back so it's always difficult, but I think we need to do the difference, we have to fight for each other as well. It will be a physical game, for sure, but we are used to it and this is a special match for us and the supporters too because it is a derby."