4 - 6 weeks if its a change of ownership (sometimes it will come thru quicker)

4 working days if the vehicle is registered to you and you order a duplicate over the phone paying £19 for the privilidge.

Use this link to see what date the last V5 was issued for your car:

www.dvla.gov.uk/vehiclelicence

(select vehicle enquiry)

If all else fails ring them on: 0870 2400010 to chase it up