This article is more than 9 months old

This article is more than 9 months old

Boris Johnson gave a rambling answer about the hunting of the snark, Fermat’s last theorem and croutons when he was asked to justify why the Conservative party masqueraded as an independent fact-checking service on Twitter.

The prime minister struggled to answer when pressed by the Guardian on whether the stunt by the Conservative campaign headquarters (CCHQ) Twitter feed undermined trust in politics.

At first, Johnson claimed the “Twittersphere is not my province”, despite his personal account tweeting many times a day to his 1.2m followers.

He then claimed wrongly that “Labour have some sort of operation which is very similar to this” before saying he “hadn’t really followed this Twitter stuff as much as others would like” and would “apprise himself” of the facts.

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Johnson then launched into a circuitous aside about how on the issue of trust there was one fact that should be found “like the hunting of the snark” or the “quest for the answer of Fermat’s last theorem”, which was Jeremy Corbyn’s position on leaving the EU.

He continued with his metaphors saying it was like the “riddle of the Sphinx or the Bermuda Triangle” and ended with a comparison of Labour’s Brexit policy to croutons in a minestrone soup.

Corbyn has committed to negotiating a Brexit deal and then putting it to a second referendum in which he would remain neutral.

The prime minister said finding Labour’s Brexit policy was the “real issue” and asked the media to “redouble their efforts and send out search parties” to find the truth.

His answer avoided the issue of whether the Conservatives were wrong to rebrand the official Twitter account as factcheckUK during last week’s televised debate.

Following the move, Full Fact, an independent factchecking service, said it was “inappropriate and misleading for the Conservative press office to rename their twitter account factcheckUK during this debate.”

Twitter also issued a statement condemning CCHQ’s behaviour and warning that any further attempts to “mislead people” during the election campaign would result in action.