[squid-users] configuring squid to go directly in case of upstream proxies are down

Is there any way through which I can control traffic from only few
clients to connect directly to internet if the upstream parent proxies
are down.
For example, in an example configuration squid forwards traffic from
client C1 and C2 to parent proxy P.

HTTP traffic from client C1 and C2 <---> forwarding squid <---> P <---> cloud

If parent P is down I want C1's traffic to be sent directly to the
internet by squid, while for C2 the connection should be dropped by
squid.

"prefer_direct off" affects traffics from all the clients.
Is there any way to use a combination of "prefer_direct off" and
"never_direct allow all/ always_direct deny all" ?

-- 
Regards,
Nipun