In May 2016, then–Australian High Commissioner Alexander Downer met George Papadopoulos, a Trump campaign foreign-policy adviser, at the Kensington Wine Rooms in London. ABC News (22 Sep 2018) reported the meeting was arranged by Erika Thompson of the High Commission and that the three of them drank for about an hour. Canberra later confirmed a May 10 date in subsequent coverage. The Mueller report used a May 6 formulation for a conversation with “a representative of a foreign government.” Horowitz later wrote May 2016 and did not print a calendar day. Do not collapse those dates into one FACT beyond: they met in May 2016.
What was said is disputed. Downer later told The Australian and Sky News Australia that Papadopoulos mentioned Russians might release material damaging to Hillary Clinton, and that there was “no suggestion” of Trump-campaign collusion. Papadopoulos has said he does not recall talking about emails and has alleged the meeting was arranged to draw him out. Those are labeled claims. The documented core is the meeting and the later official use of Australian reporting.
The New York Times (30 Dec 2017) first told a wide U.S. audience that Australian officials later passed the conversation to American counterparts after leaked Democratic emails appeared online. That is reporting. It is not a primary cable. This site does not invent the cable text.