The former England forward spent his entire professional career with the Saints, scoring over 150 goals in 443 appearances for the club, but has made no secret of his feud with club supremo Cortese, who was instrumental in the late Markus Liebherr's takeover of the club in 2009.
Le Tissier was part of a rival bid from the Pinnacle Group at that same time, and although the Saints have made great strides under Cortese's stewardship, successfully fighting their way back from League One to the Premier League, the Southampton legend revealed that he does not see eye-to-eye with the club chairman.
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"I think a lot of the stuff will come out about him when he leaves the football club and only when he leaves. He has a lot of hold over a lot of people and while the club is doing well on the pitch he will get away with it.
"When it's not quite going so well and the spotlight starts falling on other areas of the football pitch, then that's when he'll come under a little bit of pressure."
However, Le Tissier insisted that his views on Cortese will not stop him from supporting the club as they try to survive in their first season back in the top flight.
He added: "Nothing he does to me will ever stop me backing Southampton Football Cub 100 per cent when I am watching them play football.
"I think we have acquitted ourselves quite well without perhaps picking up the points that some of our play has deserved.
"I don't think we deserved to lose to Manchester United at home and, while four points is not a great total, we're still not in the bottom three."