diff --git a/britney.py b/britney.py
index a676863..bc1fb99 100755
--- a/britney.py
+++ b/britney.py
@@ -213,6 +213,7 @@ from britney2.utils import (log_and_format_old_libraries, get_dependency_solvers
                             invalidate_excuses, compile_nuninst,
                             find_smooth_updateable_binaries, parse_provides,
                             MigrationConstraintException,
+                            check_target_suite_source_pkg_consistency,
                             )
 
 __author__ = 'Fabio Tranchitella and the Debian Release Team'
@@ -477,6 +478,11 @@ class Britney(object):
             self.options.ignore_cruft == "0":
             self.options.ignore_cruft = False
 
+        if not hasattr(self.options, 'check_consistency_level'):
+            self.options.check_consistency_level = 2
+        else:
+            self.options.check_consistency_level = int(self.options.check_consistency_level)
+
         if not hasattr(self.options, 'adt_retry_url_mech'):
             self.options.adt_retry_url_mech = ''
 
@@ -1480,6 +1486,8 @@ class Britney(object):
                                 output_logger.info("  most: (%d) .. %s",
                                                    len(selected),
                                                    " ".join(x.uvname for x in selected[-20:]))
+                            if self.options.check_consistency_level >= 3:
+                                check_target_suite_source_pkg_consistency(self.suite_info, "iter_packages after commit", self.logger)
                             nuninst_last_accepted = nuninst_after
                             rescheduled_packages.extend(maybe_rescheduled_packages)
                             maybe_rescheduled_packages.clear()
@@ -1499,6 +1507,8 @@ class Britney(object):
                                                )
                             output_logger.info("    got: %s", self.eval_nuninst(nuninst_after, compare_nuninst))
                             output_logger.info("    * %s: %s", failed_arch, ", ".join(broken))
+                            if self.options.check_consistency_level >= 3:
+                                check_target_suite_source_pkg_consistency(self.suite_info, "iter_package after rollback (not accepted)",self.logger)
 
                     except MigrationConstraintException as e:
                         transaction.rollback()
@@ -1509,6 +1519,8 @@ class Britney(object):
                                            len(worklist)
                                            )
                         output_logger.info("    got exception: %s"%(repr(e)))
+                        if self.options.check_consistency_level >= 3:
+                            check_target_suite_source_pkg_consistency(self.suite_info, "iter_package after rollback (MigrationConstraintException)",self.logger)
 
                     if not accepted:
                         if len(comp) > 1:
@@ -1659,6 +1671,8 @@ class Britney(object):
                 self.all_selected += selected
                 if transaction:
                     transaction.commit()
+                    if self.options.check_consistency_level >= 2:
+                        check_target_suite_source_pkg_consistency(self.suite_info, "do_all after commit", self.logger)
                 if not actions:
                     if recurse:
                         self.upgrade_me = extra
@@ -1669,6 +1683,8 @@ class Britney(object):
                 if not transaction:
                     return
                 transaction.rollback()
+                if self.options.check_consistency_level >= 2:
+                    check_target_suite_source_pkg_consistency(self.suite_info, "do_all after rollback", self.logger)
 
         output_logger.info("")
 
@@ -1804,7 +1820,9 @@ class Britney(object):
         log_and_format_old_libraries(self.output_logger, removals)
 
         self.printuninstchange()
-        self.assert_nuninst_is_correct()
+        if self.options.check_consistency_level >= 1:
+            self.assert_nuninst_is_correct()
+            check_target_suite_source_pkg_consistency(self.suite_info, "end", self.logger)
 
         # output files
         if not self.options.dry_run:
diff --git a/britney2/utils.py b/britney2/utils.py
index fe154bd..21f9cbf 100644
--- a/britney2/utils.py
+++ b/britney2/utils.py
@@ -336,6 +336,32 @@ def old_libraries(mi_factory, suite_info, outofsync_arches=frozenset()):
                 removals.append(mi_factory.generate_removal_for_cruft_item(pkg.pkg_id))
     return removals
 
+def check_target_suite_source_pkg_consistency(suite_info, comment, logger):
+    sources_t = suite_info.target_suite.sources
+    binaries_t = suite_info.target_suite.binaries
+    issues_found = False
+
+    logger.info("check_target_suite_source_pkg_consistency %s",comment)
+
+    for arch in binaries_t:
+        for pkg_name in binaries_t[arch]:
+            pkg = binaries_t[arch][pkg_name]
+            src = pkg.source
+
+            if src not in sources_t:
+                issues_found = True
+                logger.error("inconsistency found (%s): src %s not in target, target has pkg %s with source %s"%(comment,src,pkg_name,src))
+
+    for src in sources_t:
+        source_data = sources_t[src]
+        for pkg_id in source_data.binaries:
+            binary, _, parch = pkg_id
+            if binary not in binaries_t[parch]:
+                issues_found = True
+                logger.error("inconsistency found (%s): binary %s from source %s not in binaries_t[%s]"%(comment,binary,src,parch))
+
+    if issues_found:
+        raise AssertionError("inconsistencies found in target suite")
 
 def is_nuninst_asgood_generous(constraints, architectures, old, new, break_arches=frozenset()):
     """Compares the nuninst counters and constraints to see if they improved