excluding connected routes from pbr

hi,
I have 4 /24 subnets, 2 subnets going with default gateway of table main and 2 subnets going to isp2 using pbr. I get one problem is that subnets using pbr becomes unreachable to subnets of default gateway as pbr rules takes higher precedence over main table. How to exclude locally connected routes to be excluded in policy routing without using routing marks.