Modric, who nearly joined Chelsea last summer, said he would continue to "play his heart out" for Spurs, who are chasing their first league title since 1961 and were last in genuine contention in the mid-1980s.
He has reportedly also been targeted by Manchester United, whose manager Sir Alex Ferguson is yet to find a long-term replacement for the retired Paul Scholes.
"Given all the circumstances, namely the fact that I don't want to go through the same ordeal I went through during the summer transfer period, I am almost 100 percent certain that I will stay at Tottenham until the end of the season," Modric was quoted as saying by Zagreb daily Vecernje Novosti on Thursday.
"Of course, my departure always remains a theoretical possibility if the club gets and offer it can't or won't refuse.
"I am doing my best to make sure that Tottenham lives up to the fans' expectations, we are strong and in good form so the reality is that I will stay here until May and then we'll see what happens.
"Nothing will change if I stay at Spurs, I will keep playing my heart out for the club because that's the only way I can perform and do my job," he said.
Tottenham are third in the Premier League with 38 points from 17 matches, seven adrift of leaders Manchester City and Manchester United who have both played a game more.
Spurs travel to Swansea City on Saturday.
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