You have a much more serious problem then Time Machine. Seeing as how you only have 6 GB or less of free space you really need to start doing some serious housecleaning on your disk drive. Your free space should be ten time more then what you currectly have. If you don't do this you are standing a serious chance of corrupting your disk.
You had better start either deleting or moving files ASAP.
thanks for the heads up Allan, id heard that we should always keep some space but only ever read that 10 - 15GBs free was sufficient.
Saying that, this MBP used to only have a capacity of 150GB and was always full to the brim, i was forever having to move things between external drives, its lasted me 5 years so far like that so I'm not too worried, but appreciate the advice cheers
According to Apple documentation, you need at least 9 GB of free space on the startup volume for proper operation. However, that wasn't the question. Time Machine pads out the amount of space required for a snapshot. The algorithm it uses to calculate the amount of padding isn't publicly known, but in practice, you need a backup volume that's at least two or three times the size of all the data you plan to back up to it.