Can you use IP SLA (or similar) to advertise particular BGP routes

We have a 25 node MPLS network and are going to have two sites that will act as a "gateway" into a vendor network via IPSec tunnel.  The WAN router at sites A & B will be connected to a vendor router on-site which will connect back to the vendor network via VPN.  As of right now, all routing between the vendor and the FastE port on our WAN router will be static.

My concern is that if there is a failure in the internet or tunnel, the connection to the vendor would be lost.  However, the WAN router would sill be advertising the route to the vendor network out to the WAN via BGP since it would have no idea the connection to the vendor was lost.

Is there a way to conditionally advertise a BGP network/route based on IP SLA or something similar?

Thanks.