Kim Jong Il, the enigmatic “Dear Leader” of North Korea, may be severely ill in hospital but probably remains in charge of decision-making within the reclusive Stalinist state, Japan’s Prime Minister told parliament earlier today.

With the issue of Kim’s health now the subject of uncomfortable international speculation, Pyongyang responded to the “confrontational racket” with an unusually fierce warning that it would unleash an attack which would reduce Seoul “to rubble” if the rumour-mongering did not cease.

The comments by Taro Aso follow more than a month of speculation that Mr Kim – the focus of a the all-consuming personality cult that controls North Korea – may have suffered a stroke or otherwise lost his grip on power.

If that were the case, say military analysts, the communist regime could easily be plunged into chaos as internal factions battle it out for control of the nuclear-armed state. That internal struggle could in turn spill over into worsening quarrels between the two Koreas – countries that remain technically at war despite their 55-year armistice.

Citing intelligence reports, Mr Aso told a parliamentary committee that Mr Kim’s condition was not good, but that “we don’t think that he is in a state where he is incapable of making decisions.” He added that if, as some have suggested, Mr Kim were truly unable to lead, “we would be seeing different developments” on the Korean peninsula.

Experts on North Korean rhetoric believe that the apparent ill-health of 66-year old Mr Kim has dealt the propaganda machine a heavy blow: it has long made a big play of the robust health, sporting prowess and general vigour of the Dear Leader, and, said Brian Myers of Dongseo University, has no clear mechanism ready to present the same man to the public lying incapacitated in a hospital bed.

Mr Aso was speaking a day after a Japanese television station aired footage of a man thought to be Mr Kim’s eldest son in Paris recruiting on behalf of his father the services of a French neurosurgeon. Despite being the obvious hereditary successor to Mr Kim, his son, Jong Nam, is usually dismissed by analysts as a likely future leader of North Korea and there remain few outward signs that he his preparing to take charge.

The surprise Japanese declaration came amid increasingly poisonous propaganda exchanges between North and South Korea and a sudden ratcheting of tensions across the most heavily armed border in the world. Pyongyang abruptly broke off bilateral diplomatic relations with Seoul shortly after the inauguration earlier this year of South Korea’s new conservative president, Lee Myung Bak.

Yesterday, the stakes in the rhetoric game were raised significantly when Pyongyang apparently threatened Seoul with a pre-emptive strike and the use of weaponry “beyond imagination, relying on striking means more powerful than a nuclear weapon.”

The North objects vehemently to a series of leaflet raids carried out by activist groups in the South. The leaflets – about 40,000 were dropped last week from a balloon floated over the border, contained messages informing North Koreans that their leader had been paralysed and that they should now rise-up and overthrow his “murderous” regime.

Pyongyang threatened a “just war” on the South and issued its now traditional threat to re-unify the two Koreas as a single communist state.

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