Converting lossless WMA to MP3 for FLAC format

I need to find a way to convert lossless wma files to mp3 or flac format (the end result needs to be mp3 but if we can get it to a flac format that will be good enough). This needs to be done as an automated process on a 64 bit Debian Squeeze platform. Ideally, the solution will be done using Lame but if it needs to be done using something else (ffmpeg or mplayer) I can live with that. If there is no pre-existing command line tool that can do there but there is a C++ library that can perform this conversion that is also ok but having something pre-built would be preferable.

Some information that might help:

- The WMA files are all DRM free.
- I really am not interested in any solution that involves Wine, Windows or 32 bit Linux (these are not an option)
- The solution must work from a batch process (no GUI!)
- The process must be automated as it will be part of an automated ingestion system
- This is quite urgent as it's currently blocking a very significant workflow
- Please do ask if there is any more info you need

Thanks in advance.

In case you are wondering, the format shifting I am performing is perfectly legitimate (ie. no laws are being broken and I have the copyright holders permission to undertake this process). If you have any doubt please take a look at my profile, specifically who I work for.