"We've been impressed with the way the squad have responded to the physical pressures we have put them under in the last two weeks. To a man they have all reached the standard to go to Poland," said Gatland.
"Everyone is still pretty much in the mix, but this is where the real hard work begins. "
The first camp will run from Saturday, 2 July to Monday ,11 July, with the return visit to Poland coming between 16-2 July.
POLISH TRAINING CAMP SQUAD
FRONT ROW: Scott Andrews, Gethin Jenkins, John Yapp (Blues). Lloyd Burns (Dragons). Adam Jones, Paul James , Ryan Bevington, Huw Bennett (Ospreys). Ken Owens, Matthew Rees (Scarlets). Craig Mtichell (Exeter Chiefs).
BACK 5: Bradley Davies, Sam Warburton, Martyn Williams (Blues). Luke Charteris, Toby Faletau, Dan Lydiate (Dragons). Alun Wyn Jones, Ryan Jones, Jonathan Thomas, Justin Tipuric (Ospreys). Rob McCusker, Lou Reed, Josh Turnbull (Scarlets). Andy Powell (Sales Sharks).
BACKS: Leigh Halfpenny, Richie Rees, Jamie Roberts, Lloyd Williams (Blues). Aled Brew, Jason Tovey (Dragons). Andrew Bishop, Shane Williams (Ospreys). Jonathan Davies, Tavis Knoyle, George North, Rhys Priestland, Scott Williams (Scarlets). Lee Byrne (Clermont Auvergne). Michael Phillips (Bayonne). James Hook (Perpignan). Gavin Henson (Unattached).