diff --git a/scripts/sanity.rb b/scripts/sanity.rb
new file mode 100644
index 0000000..75f6ffa
--- /dev/null
+++ b/scripts/sanity.rb
@@ -0,0 +1,29 @@
+require_relative "../models"
+
+# We should be checking polls.seats not districts.seats
+@res = repository(:default).adapter.select("
+  SELECT    c.election_id,
+            c.district_id,
+            c.party_id,
+            COUNT(c.*) AS qty_candidacies
+
+  FROM      candidacies c,
+            districts d
+
+  WHERE     c.district_id = d.id
+
+  GROUP BY  c.election_id,
+            c.district_id,
+            c.party_id,
+            d.seats
+
+  HAVING    COUNT(c.*) > d.seats
+")
+
+if @res.size > 0
+  puts "ERROR: %d districts have too many candidates standing for one party" % @res.size
+  exit 1
+else
+  puts "OK: All districts have no more candidates standing per party than there are seats."
+  exit 0
+end