In an open letter published in The Guardian (read it here) the singer James Blunt called Shadow Culture Minister Chris Bryant a 'prejudiced wazzock' and a 'classist gimp'. Both nouns mean the same thing - a stupid person. The OED's definition of wazzock is 'a stupid or annoying person; an idiot', and of gimp 'a stupid or contemptible person'.
According to the OED, wazzock was first attested in the 1970s, and it is a regional word, originally northern English. It can also be spelled wassock. The Dictionary says the origin is unknown, but it refers readers to the entry for the -ock suffix. Words ending in -ock are often diminutives, or were originally. Some, eg bullock, go back to Old English (written bulluc at the time), then a larger number of -ock words entered the language during the Middle English period eg hillock and buttock (which appeared in the 14th century). The Dictionary says that formations continued to appear in early Modern English, although the examples given are rare for me (fitchock, early 17th century, a term of contempt; wretchock, also early 17th century, a little wretch). A number of regional names for birds eg ruddock, dunnock and puttock end in -ock, and this is probably originally a diminutive formation, according to the OED. It includes haddock with this group of diminutive creatures. It also says that several familiar or disrespectful words for people, particularly females, end in -ock eg fillock (defined as 'a wanton young girl'), fussock (a fat, unwieldy woman), kittock (a wanton, mistress) and pussock (an old maid). There are other words ending in -ock, however, that, according to the OED, seem to share a general sense of ‘rounded protuberance’, ‘clump’, eg hassock, hummock, tummock, and tussock.
There are five different entries for gimp as a noun. Gimp meaning a stupid or contemptible person dates back to the 1920s and may come from the German Gimpel, a simpleton, according to the OED. It is originally a US word. Another meaning of gimp, dating also to the 1920s, and also American slang means 'a lame person'. The other, unrelated, meanings are 1) silk, worsted, or cotton twist with a cord or wire running through it, 2) a neckerchief or stomacher worn by a nun and 3) courage, 'guts'.