So what can we expect from Ukip's first woman leader, who calls her party a "change movement" and "the opposition in waiting"?
UKIP is the opposition party in waiting! pic.twitter.com/7lQWfNMMUs— Diane James MEP (@DianeJamesMEP) September 16, 2016
She is against access to the single market
James made it clear today that she will not be accepting "Brexit-lite" from the Tory party, and that Ukip still has to push hard for Brexit to go ahead properly. She does not want the UK to be a part of the EU single market, and said she will push for full control of the UK's borders. Migrants should only be allowed in if they have the right skills and social values, she said.
Her speech echoed that given by Farage earlier in the day; he accused home secretary Amber Rudd of "still fighting the referendum" and said Labour was not up to the job of opposing the Tory Brexit agenda.
Nigel Farage (@Nigel_Farage) September 16, 2016
She wants May to invoke Article 50 quickly
Today James characterised Prime Minister Theresa May as a dithering, non-committed leader and said "Remainiacs" need reminding what full independence really means.
"So, Mrs May, you’re now looking, and if you’re watching TV this afternoon you’ll be watching the opposition party in waiting," she said. "Stop the faff, stop the farce and stop the fudge and get on with it. Invoke Article 50."
She admires Vladamir Putin
Speaking about Russian aggression towards Ukraine on LBC radio in April last year, James said she looked up to the Russian leader because he is a fellow nationalist.
"I admire him from the point of view that he is standing up for his country. He's very nationalist," she said. "I do admire him. He is a very strong leader."
She was educated in a grammar school
James likened herself to May this afternoon when she said she had also been educated in a grammar school, using the point to pivot onto May's recent decision to re-introduce grammar schools in Britain. May has been stealing Ukip's policies, James said.
"Magpie May you've stolen our two per cent defence spending," she said. "Just remember where the best ideas you steal come from."