Spurs boss Antonio Conte wants to sign a new centre-back this summer and Lenglet has emerged as a key target.
Negotiations are at an advanced stage between Barcelona and Tottenham, with further talks scheduled for Thursday.
Barca are ready to let Lenglet leave on loan as they want to reduce their wage bill ahead of the new season.
The 27-year-old has slipped down the pecking order at the Camp Nou and is ready for a new challenge elsewhere.
If he were to arrive, Lenglet would likely become Tottenham’s fifth signing of the current transfer window.
The club have already brought in goalkeeper Fraser Forster, midfielder Yves Bissouma and wing-back Ivan Perisic this summer and a deal for Everton forward Richarlison is now also close to completion.
Tottenham are still keen to sign a new right wing-back, with Middlesbrough’s Djed Spence their top target.