diff --git a/Hlt/RecoConf/python/RecoConf/track_refitting.py b/Hlt/RecoConf/python/RecoConf/track_refitting.py
index aca98c6eac3da07796b18bc3b8cef6e5ee903239..fb9c6ac5fb7f60c8d465db97209a5ba12ff0db18 100644
--- a/Hlt/RecoConf/python/RecoConf/track_refitting.py
+++ b/Hlt/RecoConf/python/RecoConf/track_refitting.py
@@ -15,22 +15,35 @@ from PyConf.Algorithms import SelectFTClustersFromTracks, VPMicroClustersToVPLig
 from PyConf.Algorithms import SelectUTClustersFromTracks, UTHitClustersToUTHitHandlerConverter
 
 from RecoConf.legacy_rec_hlt1_tracking import make_ut_hit_clusters, make_PrStoreUTHit_hits
-
 from RecoConf.legacy_rec_hlt1_tracking import make_velo_micro_clusters, make_VPClus_hits
 from RecoConf.legacy_rec_hlt1_tracking import make_FTRawBankDecoder_clusters
 from RecoConf.legacy_rec_hlt1_tracking import make_PrStoreSciFiHits_hits
 
+# Algorithms to get the Pr hits
+from PyConf.Algorithms import VPLightClustersToVPHitsConverter
+from PyConf.Algorithms import UTHitClustersToPrUTHitsConverter
+
+# Algotihms to perform the fit
 from RecoConf.hlt2_tracking import get_track_master_fitter
 from RecoConf.hlt2_tracking import get_global_measurement_provider
 
 from PyConf.Algorithms import V1V1PrKalmanFilter
 
-# algorithms to get the Pr hits
-from PyConf.Algorithms import VPLightClustersToVPHitsConverter
-from PyConf.Algorithms import UTHitClustersToPrUTHitsConverter
+# Algorithms to take care of decay-tree refitting
+from PyConf.Algorithms import LHCbIDOverlapRelationTableParticleToTrack
+from PyConf.Algorithms import RecombineDecayTrees
+from PyConf.Algorithms import FlattenDecayTree
+from PyConf.Algorithms import SelectTracksForParticles
 
+from Hlt2Conf.algorithms_thor import ParticleFilter
 
-def refit_tracks(tracks, get_clusters_from_track=True, use_PrKF=False):
+import Functors as F
+
+# Optional workflow on PV association
+from PyConf.Algorithms import PVsEmptyProducer
+
+
+def refit_tracks(tracks, get_clusters_from_track, use_PrKF):
     if get_clusters_from_track:
         velo_micro_clusters_on_tracks = SelectVPMicroClustersFromTracks(
             Inputs=[tracks])
@@ -94,11 +107,65 @@ def refit_tracks(tracks, get_clusters_from_track=True, use_PrKF=False):
                 ReferenceExtrapolator=TrackMasterExtrapolator(
                     MaterialLocator=get_global_materiallocator()),
                 TrackAddClusterTool=clusters_on_track_tool,
-                MaxChi2PreOutlierRemoval=20,
-                MaxChi2=2.8,
+                MaxChi2PreOutlierRemoval=
+                9999999,  # disable - try to keep as many tracks as possible
+                MaxChi2=
+                9999999,  # disable - try to keep as many tracks as possible
                 UniqueIDGenerator=make_unique_id_generator()),
             Input=tracks).OutputTracks
 
         refitted_tracks = track_refitter
 
     return refitted_tracks
+
+
+def refit_decay_tree(input_particles,
+                     input_pvs,
+                     get_clusters_from_track=True,
+                     use_PrKF=True):
+    """ Takes an input DataHandle that contains LHCb::Particles (such as the
+    output of a trigger line), and:
+     (1) finds out which particles are basic particles, and calls the
+         track refitter on those
+     (2) takes the refitted tracks, along with the relation table,
+          to then call the DecayTree recombiner which re-combines the
+          particles together, and fits again the decay vertices.
+      
+      The output contains particles, the new vertices, the new protoparticles,
+      and again a relation table between the old particles and the new ones.
+      
+      When use_PrKF is false, the TrackEventFitter is used to refit the tracks. 
+
+      When get_clusters_from_track is false, the clusters are instead searched
+      for in the standard raw event - this only works when this is persisted. 
+    """
+    flat_particles = FlattenDecayTree(InputParticles=input_particles)
+    basic_particles = ParticleFilter(
+        flat_particles.OutputParticles,
+        F.FILTER(F.ISBASICPARTICLE),  # ideally swap to some F.HASTRACK functor
+        name="SelectBasicParticlesForRefit_{hash}")
+
+    tracks_from_particles = SelectTracksForParticles(
+        Inputs=[basic_particles]).OutputTracks
+
+    tracks_from_dst = refit_tracks(
+        tracks_from_particles, get_clusters_from_track, use_PrKF=use_PrKF)
+
+    relation_table_match_by_veloid_to_track = LHCbIDOverlapRelationTableParticleToTrack(
+        MatchFrom=basic_particles,
+        MatchTo=tracks_from_dst,
+        IncludeVP=True,
+        IncludeFT=True,
+        IncludeUT=True).OutputRelations
+
+    if input_pvs is None:
+        input_pvs = PVsEmptyProducer()
+
+    recombined_trees = RecombineDecayTrees(
+        InputParticles=input_particles,
+        InputPVs=input_pvs,
+        InputTracks=tracks_from_dst,  # the refitted tracks
+        InputTrackRelations=relation_table_match_by_veloid_to_track
+    )  # the relation table
+
+    return recombined_trees