Stand-off in centre of political power (6,3)
I believe the answer is:
number ten
I believe this is a double definition.
'stand-off' is the first definition.
(I've seen this before)
'centre of political power' is the second definition.
(I've seen this before)
'in' is the link.
(Other definitions for number ten that I've seen before include "Establishment of democratic power" , "Stand-off" , "where the PM can be found?" , "Prime Minister's official residence" , "PM's house" .)