Two thinktanks found themselves in the ring squaring off this summer. In the blue corner was the Centre for Policy Studies. And in the red – well, in this particular fight, the Social Market Foundation would certainly contest the colour assigned to it. The reason for the challenge? CPS was releasing a report entitled Bias at the Beeb? and had labelled SMF a ‘left-of-centre’ thinktank. The most surprising aspect of the report was less the unmasking by this right-of-centre thinktank of the BBC as a hotbed of latter-day Bolshevism – a familiar old hobbyhorse – than the fact that CPS included a question mark in the title of the report, implying that it might have reached any other sort of conclusion.

So who was right (or left)? CPS cited SMF’s Wikipedia entry which refers to it as left-of-centre, an entry which SMF pointed out also described it as ‘John Major’s favourite thinktank’ (perhaps an endorsement that, to the CPS, weighed in favour of the guilty verdict).

CPS head of economic research Ryan Bourne and SMF head of media and external affairs Leonora Merry exchanged very public blows, Merry pointing to her tank’s history of assorted Conservative, Labour and resolutely non-partisan directors and asking whether its proposal for ‘Facebook welfare’ was leftwing or rightwing. Members of the audience clambered into the ring; director of the National Institute of Economic and Social Research Jonathan Portes tweeted: ‘Hilarious – describing excellent & genuinely independent @SMFthinktank as “left-wing” tells you who’s biased.’

In any case, using Wikipedia as evidence is not generally regarded as the most robust way of building a case. But how much of the evidence did CPS examine? Merry landed the knockout blow, planting a big fat question mark over the stricken fighter’s motives: ‘Especially on a significant issue of public debate – ie public service broadcasting – thinktanks owe a duty to follow the evidence. Or are CPS doing something slightly different than the normal work of a thinktank? Without more evidence, I won’t stick any other name on them for now.’