The British Government has long insisted that breaches of European law by others should be rigorously policed and punished. The unpalatable truth yesterday for ministers, Tory Eurosceptics - and indeed MPs of all political hues - was that this principle is as likely to work against Britain as for it.
Amidst the pledges from a ruffled Government that yesterday's ruling will be raised at the forthcoming Inter-Governmental Conference (IGC), little attention was given to the wider impact of the ruling - which establishes the direct right of individuals to sue EU member states for compensation over what the Luxembourg court called "sufficiently serious" breaches of European law. It will be equally open to British citizens and businesses to sue other states who break the law.
The European Commission yesterday highlighted an example from 1994 when a UK company failed to secure Spanish authorisation to establish a shipping line between Spain and Morocco - until the European Commission began a legal action against Spain.
Two separate claims were involved in yesterday's ruling: unlawful British shipping registration rules under the 1988 Merchant Shipping Act aimed at curbing Spanish fishermen registering vessels in the UK so securing a significant slice of the fishing quotas, and an unlawful ban on exports of French beer to Germany.
Whether, and what, compensation should be paid is a matter for national courts. And it is still open to Britain or any other state to set conditions for vessel registration provided they are objective and do not pick and choose on grounds of nationality.
The law can cut both ways.But all three British political parties were united in their condemnation of yesterday's ruling, raising expectations that the Government will push strongly for changes to the court at the IGC.Reuse content