I believe that there is an E400 model in Birmingham- 10.7m long .
as for London:
The very first E400 shown to the public is Stagecoach's 18500, which is 10.7m long, but this bus has still not been delivered to Stagecoach, as it has not been completed.
TE655 is the first of an order for 28 buses [TE665-TE692] which were ordered by Metroline. TE665 was delivered to the company on Wendsay, and training started on Thursday, so it makes it the first E400 for London.
TE665-692 are short- 10.1m long buses, so it makes TE665 the first of it's kind!
to correct DF9321- the TEs would be used on route 24 between Pinlico and Hampsead Heath. Metroline had a road test over the route, and the buses were approved for this route, and London Buses agreed.
The buses do not use electronic blinds but a roller blind- this is again the specification of London Buses.
TE665 and not TE1- the company does not to have too many '1': DL1 TA1 TP1 TE1 etc. they prefer instead to number all the low floor buses from 1 onwards, and only change the class code.