Parliamentary sovereignty been curtailed by EU membership?
External bodies make UK law
Institutions of the EU are competent to make laws affecting the United
Kingdom, which the English courts apply irrespective of the wishes of
Van Gend en Loos v Netherlands 
"The Community constitutes a new legal order
of international law for the benefit of which the states have limited
their sovereign right, albeit within limited fields." MacMahon v DES  CD EEC Treaty on free movement workers was
applied in preference to UK regulations, which prevented C from obtaining
an education grant.
Webb v EMO Air Cargo  HL C dismissed because she was pregnant,
the Sex Discrimination Act was interpreted so as to be consistent with the
the EU Directive on sex equality.
P v S  it was held that dismissal of a transsexual for a reason
related to gender reassignment constituted a breach of Council Directive
76/207 Art. 5(1), and the UK Discrimination Act 1975 was not
compatible with EC Directive.
of Parliament incompatible with any requirement of European law can and
must be declared invalid and ineffective to
the extent of that incompatibility.