Southgate will narrow his squad down to 23 men in the coming weeks as his side prepare for challenging Group B clashes with Portugal (18 June), Sweden (21 June) and Italy (24 June), all taking place in Olomouc.
The full 27-man long list is as follows:
Goalkeepers
Marcus Bettinelli (Fulham), Jonathan Bond (Watford) and Jack Butland (Stoke City).
Defenders
Calum Chambers (Arsenal), Eric Dier (Tottenham Hotspur), Luke Garbutt (Everton), Ben Gibson (Middlesbrough), Carl Jenkinson (Arsenal), Michael Keane (Burnley), Liam Moore (Leicester City), John Stones (Everton), Matt Targett (Southampton).
Midfielders
Tom Carroll (Tottenham Hotspur), Nathaniel Chalobah (Chelsea), Will Hughes (Derby County), Jake Forster-Caskey (Brighton & Hove Albion), Jesse Lingard (Manchester United), Ruben Loftus-Cheek (Chelsea), Alex Pritchard (Tottenham Hotspur), Nathan Redmond (Norwich City), James Ward-Prowse (Southampton).
Forwards
Benik Afobe (Wolverhampton Wanderers), Patrick Bamford (Chelsea), Saido Berahino (West Bromwich Albion), Harry Kane (Tottenham Hotspur), Danny Ings (Burnley), Cauley Woodrow (Fulham).