Previous experiences with larger open source projects shows that the people who originally developed the project are mostly not left out in major new developments and enhancements (for example by a parliament). Before someone gets familiar with the code base, it makes much more sense to work with the original creators, who carry a lot of knowledge in building and operating such a project.
If nonetheless someone decides to "steal" our project, this is exactly how open source works and we will be happy that our work was obviously useful. There are many parliaments in the world. There is no way we can cover all of them by ourselves anyway.
On top of that, the decision to open source all components of the project allows re-using the concept far beyond single parliaments or regions. Theoretically a parliament in India could instantly implement Open Parliament TV. We chose a license which requires additional developments to be licensed under the same open conditions. So all new developments can be freely used by anyone else.