'My Big Redneck Vacation' Stars -- SLOPPY Drunk in the U.K.

The stars of CMT's "My Big Redneck Vacation" are PISSED ... as in the British speak for SUPER DRUNK ... as they have managed to down over 100 cases of beer in the first two months of filming, TMZ has learned.

The upcoming season centers around the Clampet family as they are shipped off to a hoity-toity British estate, equipped with a full wait staff ready to fulfill their every desire. And sources close to the production tell TMZ ... what the Clampet family desires is BEER ... and lots of it.

We're told the rednecks haven't been shy about their brewski love either ... choosing to pound over 100 cases of the golden nectar in just 60 days. We did the math (since obviously we couldn't leave it up to them) and with 24 cans per case, that comes out to 2,400 beers ... which is a whopping 40 beers a day!

As fun as all that beer chugging is ... the family says the one downside to living in the UK ... NO BUD LIGHT!