Judgment of the Court (Fifth Chamber) of 25 October 2001 in Case C-493/99: Commission of the European Communities v Federal Republic of Germany (Failure by a Member State to fulfil its obligations — Articles 52 and 59 of the EC Treaty (now, after amendment, Articles 43 EC and 49 EC) — National legislation on the contracting out of labour in the construction industry — Exclusion of undertakings not party to a collective agreement for that industry and not having an establishment in the Member State in which services are to be provided — Proportionality)