Zuckerberg will today testify before a joint hearing of the Senate commerce and judiciary committee over data misuse, before going in front of the energy and commerce committee tomorrow.
Congress is expected to ask some difficult questions of Zuckerberg on why the leak wasn't reported sooner, and what exactly Facebook's part in the scandal was.
In his opening statement, which was released by Congress yesterday, the dot com billionaire will state: "We face a number of important issues around privacy, safety, and democracy, and you will rightfully have some hard questions for me to answer.
"We didn't take a broad enough view of our responsibility, and that was a big mistake. It was my mistake, and I’m sorry. I started Facebook, I run it, and I’m responsible for what happens here."
Cambridge Analytica lashes out at critics
In a statement released late yesterday, Cambridge Analytica looked to clear up "speculation and hearsay" being circulated by the media.
"It has become open season for critics to say whatever they like about us based on speculation and hearsay,” said acting CEO Alexander Tayler.
Conjecture and rumour is being portrayed as fact, which is damaging and unfair to the company, its employees, and its clients.
It would be impossible to address the hundreds of articles and broadcast segments that have misrepresented Cambridge Analytica or replicated false statements made by those focused on creating a political scandal.
The company went on to list 10 facts in response to accusations that have been levelled at the company.
Cambridge Analytica said that it had broken no laws, and had not "hacked" Facebook, but got the information from a research company (GSR) who licensed the data to them, something which hundreds of data firms do in a similar fashion.
It also claimed that it did not use the GSR data in the US presidential election or during the Brexit referendum.
The data analytics company also argued that it only collected data with "informed consent" from participants.