The Young Lions head coach successfully led his squad through the qualifying stages without defeat, culminating in an impressive play-off performance against Croatia last month.
Southgate's Under-21s qualified for the Euro Finals by winning 11 of their 12 games
The likes of Raheem Sterling, John Stones, Luke Shaw and Saido Berahino have all played an important part in the qualification stages over the last 13 months before being selected for Roy Hodgson’s senior squad.
There are also a number of regular senior players still eligible for the competition, but haven’t previously featured for the Three Lions under Southgate, such as Jack Wilshere, Alex Oxlade-Chamberlain, Calum Chambers and Phil Jones.
And Hodgson has now revealed that he will make all of the young players in his group available for selection for the Finals next June, should Southgate wish to pick them.
"It's a very simple policy, after Gareth Southgate has picked his squad, I will pick my squad [for Republic of Ireland and Slovenia]," he said.
"He'll speak to me and he'll tell me what he wants to do, but I can't be fairer than to say it's his choice."
Southgate has previously spoken of the excellent team spirit in place amongst the squad of players which has served him so well since he re-joined The FA last September.
England U21s boss Gareth Southgate and his squad have created a strong bond and team spirit during Euro qualification
And the former Middlesbrough boss has also stated that he is keen to reward the players who have figured in England’s unbeaten qualifying campaign on the road to Czech Republic.
"The decision is Gareth Southgate's and his alone and when he makes his choice of the players, he'll be under no pressure from me whatsoever," added Hodgson.
"We've got a lot of players these days, we can deal with four or five absentees. If they're available for me, that's fine too.
"It cuts across two senior games and it would also mean any senior players playing in the tournament in Czech Republic would be playing three tournaments in a row, three summers in a row without any break from football at all."
