The Lilywhites sit just two points adrift of fourth-placed City in the standings and the Belgium international believes that the team has already proven itself capable of recovering from heavy defeats in the past.
Speaking to Sky Sports News, Vertonghen said: "You cannot write us off. We did not do well in this period last year with losses against Wigan and City and Arsenal.
"But we then had incredible months in December and January and I think that is what we are aiming for now.
"We want to do well in those two months and then I think we can be back easily because the top half of the table is so strong and everybody can win."
Spurs host champions Manchester United in North London tomorrow afternoon.