OK - the 'decker you can see the front of is of course an AEC Regent III RT of London Transport. It's not clear from the screen captures how many there are altogether, either 2 or 3!
The coaches:
There are two superb Bristol LS6G with Eastern Coachworks body in the livery of Royal Blue, separated by what looks like an AEC Reliance of Grey Cars. The Bristol LS that you can see the registration plate for, that appears to be MOD974 or MOD976, which would make it Southern National 1287 or 1289. Both Southern National and Western National had coaches in Royal Blue colours, this one is definitely Southern National. If anyone can review the footage and get the registration for definite, that would be great!

History and photographs of MOD974:
http://www.bristolsu.co.uk/ls/operatordetails/southernnational/mod974.htm

History and photographs of MOD976:
http://www.bristolsu.co.uk/ls/operatordetails/southernnational/mod976.htm