Several eastern European states condemned Thursday a new EU reform of hauliers' work conditions, branding the measure "protectionist" and with some leaving open the option of a legal challenge.

The "mobility package" reform passed by MEPs on Wednesday evening came after months of bitter wrangling between western and eastern member states and aims to ensure minimum working standards across the EU, for example by mandating rest breaks for drivers and regulating the practice of posting drivers abroad.

Hungarian Justice Minister Judit Vargas said that MEPs had "given protectionism the go-ahead", adding that some of the provisions of the reform "are contrary... to basic freedoms relating to the single market".

Romania's foreign ministry meanwhile blasted what it called the "restrictive and disproportionate" reform, adding that Romania "reserves its right to use all available options, including launching an action at the EU Court of Justice".

The reform means road haulage companies will have to allow long-haul drivers to return home at regular intervals of three to four weeks.

Some call the reforms an attack on 'basic freedoms relating to the single market'
Some call the reforms an attack on 'basic freedoms relating to the single market' AFP / GUILLAUME SOUVANT

It also mandates a weekly rest period which must be taken outside the vehicle, with accommodation reimbursed by the company.

Vehicles will also have to return to the company's operational centre every eight weeks, which eastern countries warn will have negative environmental consequences if extra journeys have to be made.

The Union of Romanian Transporters (UNTRR) said that the reform "sounds the death knell for international road haulage in western Europe by eastern European companies".

It said that the costs entailed by the reform would mean a 10 to 14 percent loss of revenue for businesses, with a third of operators and 200,000 jobs in the sector at risk over the long term.

Bulgaria's transport ministry also called the reform "unbalanced" and "discriminatory", adding in a statement that it was also considering a legal challenge.

The issue of conditions in the sector has pitted eastern countries -- also including Poland, Latvia and Lithuania -- against Western states like France and Germany who want to clamp down on so-called "social dumping" driving down standards.