Perhaps "occasional" wasn't the right choice of word. They have regular columns, yes, but when the Guardian goes into attack mode against the left, these writers either don't appear or are drowned out by others in the paper.

I spent some time helping collect examples of the Guardian's output during its obsession with attacking Jeremy Corbyn. Try to find comparable coverage in support of Corbyn in the Guardian to offset these attack pieces published between 2015 and 2017: https://theguardian.fivefilters.org (note that Owen Jones, far from being a dissenting voice, joined in with the attacks here, later apologising).

David Graeber tweeted a link to this at the time - after all the Guardian's doomsayers were proven wrong. https://twitter.com/davidgraeber/status/874853587880423426

After some time the Guardian intensified its attacks, this time focusing on spurious claims of antisemitism. They refused to run Graeber's piece defending Corbyn. Again, see if you can find comparable coverage defending Corbyn in the Guardian compared to ones trying to tar him with the antisemite brush: https://theguardian.fivefilters.org/antisemitism/

And that's of course not mentioning the study that found the Guardian to be one of the most innacurate in reporting claims of antisemitism (more so than even the Sun and the Daily Mail). That little fact is still the pinned tweet on Graeber's Twitter account, which must really annoy the Guardian when his name's trending on Twitter. https://twitter.com/davidgraeber/status/1210322505229094912