From the Journal of Commerce:

The European Commission on June 20 decided to refer Spain to the European Union Court of Justice regarding its rule on hiring port labor in several Spanish ports.

Currently, cargo-handling companies in these ports, including the ports of Barcelona, Algeciras, Valencia and Bilbao, are not allowed to resort to the market to employ their staff. Instead, the rule requires cargo-handling companies to participate financially in the capital of private companies, which in turn provide them with the required workforce. Only when the workforce proposed by these private companies is not suitable or not sufficient can the cargo-handling companies freely hire staff from the market.

As a result, cargo-handling providers from other EU countries wishing to establish themselves in Spanish ports may be discouraged from doing so because of these restrictive labor practices, which violates EU treaty rules on freedom of establishment, the EC said.

More at the JOC