The Swedish climate academic Andreas Malm has condemned a travel ban imposed on him by the UK government as a “drift into authoritarianism” amid criticism of the move.

Malm, the author of How to Blow Up a Pipeline, said he had been “kept in the dark” by the UK’s immigration authorities over the reasons for his electronic travel authorisation (ETA) being revoked.

He said he had only been told that his presence in the UK was “not considered to be conducive to the public good”, as the Guardian revealed .

Speaking to Radio 4’s Today programme on Friday, he speculated that the only plausible rationale for the ban was his advertised appearance at a conference next Wednesday alongside Huda Ammori, a co-founder of the proscribed group Palestine Action.

He said: “I cannot see any other explanation than the scheduled appearance of me on stage for a panel on Wednesday evening in London, together with Huda Ammori.…