No current serving politician that I am aware of (and I'm happy to be corrected, there may be one or two out of the 645 honorable members who have sons or daughters serving or have served) can say that
Mark Lancaster, MP for Milton Keynes is a TA Major in the Royal Engineers, and his bio says:
"Mark continues to serve in the Territorial Army as a Major and spent the 2006 summer recess on active service alongside our troops in Afghanistan. This was the third time that Mark has volunteered for active service since 2000, having previous [sic] served as part of the NATO peacekeeping force in both Kosovo and Bosnia."