All door staff must sign up for a licence from the new Security Industry Authority by the 13 December deadline.

Police said there are 679 door staff logged under the current system, but only around 400 have completed the training to receive the new licence.

Directors of door supervisor companies and managers of door staff must also obtain the �190 licence.

'Closed down'

To get it, they must undergo a criminal record check and if they intend to work on the door they must also complete the training.

Insp Graham Strange of Cleveland Police said: "With up to 140 licensed premises in the area regularly using door staff, unless people act now by signing up for the training and then applying for their licence, some pubs and clubs could find themselves either breaking the law or operating without a sufficient number of door supervisors.

"The run up to Christmas will be a particularly busy time for the licensing trade. There will be a significant demand for door supervision and that is the time when there could be a shortfall."

The Security Industry Authority is an independent body, set up by the government under the terms of the Private Security Industry Act 2001.