No even though the Workboat Code Edition 2 states that they can this is incorrect.
As per the MCA Codes team:
Clarification: Workboats under 150GT Built Prior to 1968 SI 1998/1609 is the enabling regulation under which the Workboat Codes are hung.
http://www.legislation.gov.uk/uksi/1998/1609/made
This regulation defines a small vessel as being no longer than 24m in load line length. There is no age allowance in SI 1998/1609 as otherwise provided for vessels operating for Sport and Pleasure in SI 1998/2771, therefore workboats are restricted to 24m LLL regardless of age. We acknowledge that this is an error in Workboat Code Edition 2 and are working to rectify this – however SI 1998/1609 as the enabling regulation takes precedence.