They are among 12 honorary degree recipients from the arts and cultural sectors.
The designer hosted old friends at a new venue, The Ned.
May called a surprise snap election while Rush argued on behalf of British fashion in parliament in the run-up to Brexit.
The British prime minister said she needs a strong hand in Brexit negotiations.
Guests included Roksanda Illincic, Christopher Kane, Mary Katrantzou, Nicholas Kirkwood, David Koma, Erdem Moralioglu and Simona Rocha.
Three new appointees will support ceo Caroline Rush.
The program aims to provide financial support and offer career paths in alternative areas of the industry.
The documentary is narrated by the British musician — and cheese-maker — Alex James.
London showcase will run through Monday, Jan. 11.