Is that labour Banner at West House legal?

A large new banner appears at West House, raising questions whether this is legal and if this should be investigated. 

In May this year it was reported that the Vale Council were investigating Penarth Trinity Methodist Church banner

There was also a row about advertising banners being installed by builders in Penarth Marina and by Westbourne School on its fences. 

West House is Penarth Town Council’s HQ on Stanwell Road – a building which – over the years – local council-tax and rate-payers have already had to buy twice-over and which recently has had a £££ makeover.  

West House is also used for constituency sessions by Stephen Doughty MP – 

VALE Labour Cllr Lis Burnett
Holds occasional surgeries at
Westhouse   

We don't know if he or the labour Cllrs pay to use it. 

Stephen Doughty MP

The constituency sessions involve the attendance of a member of council staff to open up and lock up afterwards so it’s not cost free.
  Bearing in mind the Vale council is so short of funds it couldn't even provide a few flowers on Penarth roundabout.

Westbourne School banners