The Labour MP said she was confident that her party could win an election, and that she was "looking forward" to implementing new policies.
The shadow home secretary says she has reported the business tycoon for "offensive" social media posts about her.
Diane Abbott has criticised the government's plan to stop freedom of movement with the EU in the case of a no-deal Brexit.
The Labour MP has retweeted a number of critical tweets about the party's deputy leader Tom Watson.
The shadow home secretary told climate change activists they had done an "amazing job" in drawing people's attention to the "climate emergency".
Political activist Ava Etemadzadeh condemned the Labour MP's comments defending the controversial whistleblower.
The politician claimed Julian Assange was being pursued because he "exposed wrongdoing" and not to protect "US national security".