Catalysis of the reaction: N-acetyl-D-glucosaminyldiphosphoundecaprenol + UDP-D-glucose = beta-D-glucosyl-1,4-N-acetyl-D-glucosaminyldiphosphoundecaprenol + UDP.
UDPglucose:N-acetyl-D-glucosaminyldiphosphoundecaprenol 4-beta-D-glucosyltransferase activity