Hart's recent performances for club and country have come under fire, with his display in City's 3-1 defeat to Bayern Munich in the Champions League on Wednesday adding fuel to the fire.
Seaman has declared that criticism did nothing to help him during his spell as England number one, while insisting that there is no doubt Hart will start England's upcoming World Cup qualifiers against Montenegro and Poland.
He told ITV Sport: "When I was playing, if other goalkeepers criticised me, it would do my head in. As an ex-goalkeeper, you know what they're going through, and you know criticism is the last thing they need.
"I had it with big, high-profile ex-goalkeepers having a go at me, it doesn't do any good at all. Everyone in England should be backing the goalkeeper and the team.
"Definitely. No doubt whatsoever [over Hart's England place]. You can't put an inexperienced goalkeeper into those games. Scott Carson [against Croatia in 2007] is a massive example of that."