"I see the Lions tour as a motivation for the players. I told them we want as many of them as possible to go on the Lions tour," said Lancaster.
"It's a massive thing for the players and I think it helps them become better players by going to represent England within the British & Irish Lions at the highest level. I also want the players to feel we're behind them in supporting them in that journey.
"We want as many as possible on the tour and then I can take some development lads to Argentina."
Leicester Tigers flanker Tom Croft, who scored two tries on his Test debut against the Springboks in 2009, is the only current Lion is England's Senior EPS.
"We need seven world class players in our team and I define world class players as being in the top three in their position in the world," added Lancaster.
"The Lions are the benchmark of the four northern hemisphere sides and if you're not playing well enough to tour with the Lions, then you can't be in the top three in the world.
"It will be a good barometer for us as I saw various selections for the Lions pre-South Africa and we didn't have very many in there. Teams are made up of the overall sum of their parts but equally we want some stardust in there too."