I am about to make an event and going to invite some political figures. The event must be a politic free event. But, I can't control the action of these political figures. This year is the year leading up to the presidential election in my country. So, the chance of promoting one of the president candidate is very likely to happen.
The political guests are supposed to give a speech and make small talk with other guests. There are no discussions.
How to professionally make the political figure to not speak about politic in the event?