Dominic Cummings has hit out at a political system which encourages politicians to focus on “Twitter and gossip column stories about their dogs” rather than major existential threats.

His comments are likely to be seen as a thinly veiled swipe at Boris Johnson’s fiancee Carrie Symonds who was widely seen to have engineered his departure from No 10 last month in a bitter Downing Street power struggle.

The Prime Minister and Ms Symonds acquired their rescue dog, Dilyn, in a blaze of publicity shortly after he took office.

Mr Cummings, who is in the process of leaving his post as the Prime Minister’s chief adviser, picked an incident in 1983 when a Soviet missile officer potentially averted a nuclear war when he ignored an alarm warning of an incoming US ballistic missile attack because he believed, correctly, that it was false.

“We have fluked many similar episodes since the 1960s. ‘Launch on warning’ protocols combined with flawed early warning systems remain a huge danger today. Nuclear and biological weapons are proliferating,” he wrote.

“Issues of existential importance are largely ignored and our political systems incentivise politicians to focus more on Twitter and gossip column stories about their dogs.”

He also appeared to take a sideswipe at the former Cabinet Secretary Lord Sedwill – with whom he also reportedly clashed – suggesting that it was his successor, Simon Case, who had recognised the problems with the nuclear deterrent.

“In Britain, parts of the nuclear enterprise have rotted from years of neglect, though thankfully the new Cabinet Secretary knows and cares and is acting to remedy this,” he wrote.

“In America and Russia, security disasters are routine. As Covid has shown, far greater intellectual and material resources ought to be deployed on such apparently low-probability, high-impact events.”