It depends how Germany now understands the NSA and all its help setting up West German telco systems after WW2.
German decryption teams found gainful employment in 1945 with the UK/US TICOM
https://en.wikipedia.org/wiki/... teams.
Generations of West Germans worked with the NSA and traveled to the US to view emerging US systems, hardware and other crypto systems.
That kind of generational contact has allowed the US to handle elite German crypto staff and keep them away from any domestic West/German legal or political process.
That deal with the USA gave West German total mystery over its internal and international communications networks for decades.
So a few German elected political leaders are facing the might of decades of US/German military friendship at a top level beyond German law.
Other US West German intelligence contacts can be understood from the Gehlen Organization years
https://en.wikipedia.org/wiki/...
All German political parties know is their communications have been tasked by the USA even when declared safe by decades of expert West/German crypto officials.
Any inter party or elected party efforts on this topic that where discussed over a secure German network of any kind would have been intercepted.
Given the years of US/UK access to West/German political communications it would be hard to find a cleared German crypto expert who could even present the scope of what was done to German communications networks.
The clearance levels that exist in Germany for German experts would not be of any use to any committee and no German staff with US systems access would be cleared by the US to talk to anyone in Germany at any level.
The US and UK have that domestic legal staff aspect covered in an nation they 'help'
:)
US security work given to local German staff out rank any domestic German legal traditions or German fact finding political settings.