asked Her Majesty's Government:

Whether traffic wardens employed by local authorities are required to identify themselves to motorists and others when so requested, in the same way as police officers. [HL3893]

A civil enforcement officer (CEO) employed by a local authority must wear a uniform when serving a penalty charge notice or immobilising a vehicle. 

The uniform must be in accordance with the guidelines issued by the appropriate national authority. The Department for Transport's guidelines for England state that the uniform should clearly show that the wearer is engaged in parking enforcement, the name of the local authority/authorities on whose behalf he is acting and a personal identity number. The guidelines also recommend that a civil enforcement officer should carry a photo-identity card but the name of the CEO should not be included to protect the safety of staff.