Interesting if true. This should easily be backed up with video evidence instead of just "sources". Note that the author, Harding, has been previously tied with publishing false articles. All other sources, including Wikileaks, have clearly stated this article is untrue.
The reputation of Wikileaks or The Guardian are going to take a big hit here.
https://www.theguardian.com/us-news/2018/nov/27/manafort-held-secret-talks-with-assange-in-ecuadorian-embassy