Any time there is a death of a major figure it has a huge impact on governing bodies. Especially when it is a sudden, early, or violent death. This type of thing effects everyone and more than likely will have a ripple effect through Parliament. If it does not then who knows.
Following the death of MP Cox, both sides of the debate on EU succession stopped campaigning. Parliament must be understanding that the debate has turned into something ugly and hateful. This will have far reaching effect on both the campaigning and the steps Parliament takes after the votes have been cast. Every Parliamentarian will be wary of personal safety, as well as how deeply the hatred and passion run in the community.
Death in any organization has a negative impact. In this case, the death of MP Cox will also have a negative impact. The word terrorism has been brought into the minds of others whom were working in Parliament which can bring fear and intimidation to the other members. I believe this fear will ripple through Parliament and have a negative impact.
The murder of MP Cox will definitely leave Parliament members shaken. Her death will raise concerns for security of government officials. Also, her death will force security agencies to take threats against officials more seriously. Most likely, Parliament will approve additional funding for security agencies, and additional protection for government officials.