apt config to acquire http but not https proxy?

Hi, Google is failing me. I know I can use acquire::http::proxy in apt.conf.d to set a proxy server, but this seems to make it used for both HTTPS and HTTP traffic -- however I only want to use it for HTTP traffic. Any suggestions? (Things not to say: * Use iptables to transparently proxy port 80 * Get a better HTTP proxy that support SSL ) Toby