Leicester duo White and Kay will have the chance to impress against their own country, with both players having been part of England's World Cup winning campaign in 2003.
The pair are joined by another Englishman in the starting line up, with Wasps and soon to be Toloun wing Paul Sackey also included.
Williams, who has featured in each of the last three Lions tours, starts in the back row against Cardiff Blues club-mate Xavier Rush and New Zealander Rodney So'oialo, who tasted success against the Lions with the All Blacks back in 2005.
The Baa-Baas will arrive in London full of confidence thanks to the presence of Heineken Cup winners Florian Fritz, Cedric Heymans, Jean-Baptiste Elissalde, Byron Kelleher and Census Johnston and Amlin Challenge Cup victors Casey Laulala, Williams and Rush.
George Smith, who faced the Lions with Australia eight years ago, is named among the replacements bench that also features Biarritz skipper Jerome Thion just a week after his Heineken Cup heartbreak.
Barbarians (v England): Paul Warwick (Munster); Paul Sackey (London Wasps), Casey Laulala (Cardiff Blues), Florian Fritz (Toulouse), Cedric Heymans (Toulouse) ; Jean-Baptiste Elissalde (Toulouse), Byron Kelleher (Toulouse) ; Rodrigo Roncero (Stade Francais), Benoit August (Biarritz Olympique), Julian White (Leicester Tigers), 4 Ross Skeate (Toulon), Ben Kay (Leicester Tigers), Rodney So'oialo (Hurricanes), Martyn Williams (Cardiff Blues), Xavier Rush (Cardiff Blues, captain)
Replacements: Ken Owens (Scarlets), Census Johnston (Toulouse), Jerome Thion (Biarritz Olympique), George Smith (Brumbies), Pierre Mignoni (Toulon), Fabrice Estebanez (Brive), David Smith (Hurricanes)