John Fortune and John Bird, "The Long Johns," explain the subprime mortgage crisis on the South Bank show.
The conceit is that an expert, "George Parr," played interchangeably by either Mr. Bird or Mr. Fortune, is interviewed by an erudite chat show host played by whoever isn't playing George Parr. (Clear?)
The satire is especially brutal because largely fact-based.
See also: "George Parr" videos on YouTube, but especially George Parr on Iraqi Oil and George Parr, Conservative MP.