i believe the MD-80's were purchased with the idea that the UK charter market lacks cheap aircraft in the 150-170 seat market - and at least 2 were earmarked for Palmair. Palmair are trying to expand their 3 and 4 hour sector flights and these are ideal for that purpose.
no idea about the 146's though, unless they will be used as executive aircraft, replacing the exec 737's that have since gone down-under.