Mr Gresty initiated last week's successful prosecution of calf dealer and exporter Albert Hall Farms for animal welfare breaches.
He said while he welcomed any improvement in animal welfare legislation, the new Welfare of Animals During Transit Order 1994 failed to address problems faced by trading standards officers in enforcing present legislation.
'In fact, it has even more problems associated with it. Far from tightening the legislation, as stated by Mr Waldegrave, it will hamper enforcement', claimed Mr Gresty.
He said introduction of the Order should be postponed so that the problems in it could be put right.
'It is unclear. It does not have clear definitions of what are classified as journeys. It has associated with it a code of practice, which has no statutory backing whatsoever, which lays down resting times and so on. Unless that is made statutory or those times are laid down in legislation, we cannot enforce them.
'I also believe that this reduces the responsibility on people involved in the livestock transportation industry. At present we are able to put the responsibility on exporters and on hauliers. The new legislation tends to limit it to one of those, and I think that is a retrograde step', said Mr Gresty.