What actions will result least damage in the MI5 Activity Alert - Parliamentary acting in a suspicious manner plot?

During the MI5 Activity Alert – Parliamentary acting in a suspicious manner plot, you have (as far as I could track) 2 players:

• Parliamentary Under Secretary of State for Public Health
• Visitor to Minister

The best I could do was to ransack the Parliamentary to grab the vial and smear him (problematic political damage).
The smear will result in less political damage, but there was nothing else I could do to deal with the situation. Everything else (eliminate or abduct) will result in a lot of exposure to the operation.

Is there an action or a set of actions in any specific day that will result in a better output?