If you want to play chess, let's play!
Stick on an amendment that phases in changes over 10 years so that the parties can build up their grass roots fundraising machines. During the 10 year transition, the rule would be that public funds are only available such that public funding + private donations cannot total more than 15 million a year (or, whatever is deemed to be the number that best screws over the
Tories, and only the Tories).
After all, if it's about principle, certainly this seems fair. It's not without precedent - as Stephen Taylor points out, Obama opted out of public funding in the states. And if it's about making sacrifices in light of tough economic times, well, this would be a grand selfless gesture on the part of the Tories.
Your move Steve.