The England coach, speaking at the launch of a new pounds 2m sponsorship deal with the manufacturers of the chocolate bar Snickers, said standards will drop further if the government fails to put enough emphasis on funding the game at schools level.
The Snickers deal will both back the national team and promote schools' football, and Venables said: "We cannot think that football will always be there as our most popular sport.
"We've got to protect football. If that falls back and we fall behind everybody else we will lose everything. We've got to get facilities for schools."
He added: "It worries me greatly when we build on fields and parks and the streets are full of cars because there is nowhere for the kids to play.
"I used to go to Scandinavia for pre-season tours with QPR and Crystal Palace and we were the better teams then. If we want to get back on top again we've got to open up our thinking and make sure we don't lag behind. I don't know what the sums are, but I know money is needed to safeguard the future of our game."
Yet Venables insisted his side are still on course for success in Euro '96 - despite widespread criticism in the aftermath of last week's goalless draw in Norway. He said: "If we don't change our way of thinking, we won't change our results.
"I understand the criticism and that questions will be asked when changes are made. But it could be said that we've not been too good in the past, so let's try to change it.
"If it is a bit frustrating let's still stick with it and not just jack it in. We've got to be bold and go through the frustration and the criticism."Reuse content