As per PR comments:

- Remove Organisation.services
- added backref='services' to Services.organisation relationship and removed redundant foreign_keys argument.

app/models.py

@@ -349,12 +349,6 @@ class Organisation(db.Model):
     active = db.Column(db.Boolean, nullable=False, default=True)
     created_at = db.Column(db.DateTime, nullable=False, default=datetime.datetime.utcnow)
     updated_at = db.Column(db.DateTime, nullable=True, onupdate=datetime.datetime.utcnow)
-
-    services = db.relationship(
-        'Service',
-        uselist=True,
-        backref=db.backref('services'))
-
     agreement_signed = db.Column(db.Boolean, nullable=True)
     agreement_signed_at = db.Column(db.DateTime, nullable=True)
     agreement_signed_by_id = db.Column(
@@ -480,7 +474,7 @@ class Service(db.Model, Versioned):
     go_live_at = db.Column(db.DateTime, nullable=True)
 
     organisation_id = db.Column(UUID(as_uuid=True), db.ForeignKey('organisation.id'), index=True, nullable=True)
-    organisation = db.relationship('Organisation', foreign_keys=[organisation_id])
+    organisation = db.relationship('Organisation', backref='services')
 
     email_branding = db.relationship(
         'EmailBranding',