From The Internet Movie Database:

Buried in the sheer oddity and downright perversity of the humour there is a deep pathos. People of all classes from Lord to lunatic try through activities and language to cling to a civilization represented by heaps of objects. The horrors of holocaust are tempered by humour arising mainly from the ridiculous pretensions of the cast. Every mainstay of British middle and upper class culture has been made absurd - some of the characters are busy mutating into absurd objects - a bed sitting room, a wardrobe, a parrot. The humour is zany, the one-liners often mixing double entendre, understatement and naievity with real pathos. Arthur Lowe as the pompous father, Mona Washbourne as the all-sympathetic mother can bring a lump to the throat.

The nearest rival to Milligan's and Antrobus' satire is to be found in Swift. Lampooning society after it has endured the very worst of tragedies and demonstrating through a torrent of absurdities, that human decency survives is something difficult to sustain in text, but this Fellini-like panorama could never be contained by the pages of a book. It almost defines one of the things which film can do best.

It is ragged and patchy - but a film which includes Harry Seacombe as a 'regional seat of government' defies conventional criticism!