Entwood, very interesting - if rather shocking - revelation.

Have you a link to confirm this sorry state of affairs?
Nope ... it was explained to me by a Barrister on Thursday, I work within the court system and after a hearing had finished I asked him why he had pushed for the 6 week sentence when the Crown had asked for 4.
Crown Prosecutor confirmed it...

Apparently the original ECL proposals would have ensured that a minimum of 7 days was always served, but that was disregarded as it didn't release enough prison places....

Remember .. this whole thing is because the Government has refused to build more prisons, the EU has "backed" the "prisoners rights", so there are fewer prison places than there used to be, and using Police Stations is now regarded as a no-No, yet more crime is being committed due to the recession ... but there is nowhere to house the prisoners

EDIT .. found this ... the original 2007 ECL info to Probation Service
The 18 day bit is in the last para of page 1
http://www.probation2000.com/pit/circulars/PC22%202007.pdf