TUNSTALL RESPONSE LIMITED

BARCLAYS BANK PLC

DEBENTURE

NATIONAL WESTMINSTER BANK PLC

A DEED OF ACCESSION (MADE 16TH JUNE 1998 MADE BETWEEN (1) THE COMPANY AND (2) NATIONAL WESTMINSTER BANK PLC (THE "SECURITY TRUSTEE") AND (3) TEDCO PLC ("TEDCO") (THE "ACCESSION DEED")) TO A COMPOSITE GUARANTEE AND MORTGAGE DEBENTURE (MADE 18TH MAY 1998 BETWEEN (1) TEDCO AND (2) THE SECURITY TRUSTEE (THE "DEBENTURE"))