Assange worked with Rusbridger, Guardian's editor in chief at the time, I think. So .... the guardian should go to the guardian and get their help! :-)
0: https://www.jonathan-cook.net/blog/2016-02-05/no-fair-hearin...
1: https://www.jonathan-cook.net/blog/2018-11-28/guardian-vilif...
2: https://www.jonathan-cook.net/blog/2020-09-26/guardian-assan...