Five points currently separate the sides, with Sunday's clash representing a major opportunity for Claudio Ranieri's men to put pressure on PSG.
While the clash is likely to be the showpiece of this week's fixtures, the gloss has been taken off somewhat by the absence of injured pair Edinson Cavani and Radamel Falcao.
PSG forward Cavani has been ruled out for a number of weeks with a thigh injury while Monaco's Falcao is a long-term absentee, having picked up a knee injury.
It means Zlatan Ibrahimovic will carry much of the goalscoring responsibilities, having scored five goals in his last five matches, while Monaco could hand a debut to recent signing Dimitar Berbatov.
Lille have little chance of catching Laurent Blanc's side, sitting 13 points off the top, and have seen their hold on third place come under threat after poor recent form.
Rene Girard's side are without a win in their last five league games and failure to beat Sochaux could allow Saint-Etienne to take their place in the third and final UEFA Champions League spot.
They travel to Toulouse having won 12 games of their opening 23 Ligue 1 matches for the first time since 1981-82 while, at the foot of the table, Ajaccio will look to turn their recent draws into only a second league win of the campaign against Rennes.
Even victory would not move them off the foot of the table although it could close the gap to Sochaux and Valenciennes - the latter hosting Nice at the Stade du Hainaut.
Nantes will hope to recover from their last-gasp Coupe de la Ligue defeat to PSG when they welcome Lyon while Marseille, a place above Remi Garde's side in the table, host Bastia.
Guingamp, without a win in eight top-flight matches, host Reims while Evian can put further distance between themselves and the drop zone with a win at Montpellier.
Bordeaux take on Lorient at the Stade Jacques Chaban-Delmas on Sunday with Francis Gillot's side able to move fifth with victory - provided Lyon and Marseille's results go their way.
