The 23-year-old was expected to sign the lucrative new five-year deal worth £140,000-a-week, especially after his agent Mino Raiola said he was “99.9999 per cent” sure he’d sign last December.
However, Lukaku is insisting to a release clause of no more than £70million to be included in the new contract.
At the end of last season, Chelsea tried to take him back, following his his record £28m move from Stamford Bridge to Merseyside three years ago.
Everton turned down a £57m bid from the Blues.
But they might be forced to do a deal in the summer, when Lukaku has just two years remaining on his contract. The Belgium international is also keen to play in the Champions League next season.