In secret telephone conversations with activist groups based in democratic South Korea, residents of the North have revealed their own doubts about the man anointed as the Great Successor and Supreme Commander, despite all the revolutionary rhetoric with which they are bombarded.

“He is a four-star general aged 28,” observed a trader, Im Seong-taek. “When did he do his time in the army to get those stars? It’s nonsense.”

A farmer in the far north of the country said: “He doesn’t seem to be much use. A young person with his belly sticking out looks lazy.”

Such comments are the fruits of a growing effort by South Koreans – often aided by defectors from the North who have made their way to Seoul, the capital of the South, by circuitous routes – to use gradually spreading mobile telephone technology to find out what North Koreans really think.