Is it possible to disable Google Play updates?

Is it possible to disable updates to Google Play and Google Play Services? I have automatic updates switched off, but this 2 Google apps are upgrading itself without my permission, and I can only helplessly watch how the free space is decreasing to the amount, my Gmail synchronization is not working anymore (related to https://android.stackexchange.com/questions/3399/does-the-gmail-app-stop-syncing-once-the-low-on-space-message-appears?lq=1) . I know I should root my phone to move apps to SD completely, but I don't want to do that before the end of summer, to not risk not having mobile internet in case something goes wrong. # Edit: Device is a HTC Desire A8181, aka HTC Bravo.