Two days of disruption on the London Transport system last week (and the probability of two further days this week) has triggered speculation from the BBC's political editor and others that this could lead to a change in the law.

One feature of the current law that has been criticised by employers’ organisations is that a strike can go ahead with only a minority of the union members balloted supporting it. For example since 2011 the CBI has called forthe introduction of a 40% threshold of balloted union members supporting industrial action, in addition to a simple majority of those actually voting. The London Mayor, Boris Johnson, has said that there should be a participation threshold of 50%, though he appears to have stopped short of calling for an absolute majority of union members balloted supporting the strike.

On the other side union leaders have long argued that Britain’s legislation is among the most restrictive in Europe. Two aspects are currently being challenged by the RMT union before the European Court of Human Rights: the ballot notice requirements and the ban on secondary action. Whatever the merits of this challenge, it does illustrate that like so many other aspects of our employment law, the legislation restricting industrial action is not purely a matter for the British government.

Any statutory restrictions on the freedom of organised labour to call a strike need to comply with Article 11 of the European Human Rights Convention. This limits such restrictions to those “necessary in a democratic society in the interests of national security or public safety, for the prevention of disorder or crime, for the protection of health or morals or for the protection of the rights and freedoms of others.” This familiar rubric, which appears in a number of other articles of the Convention, will no doubt give those responsible for framing any new legislation plenty of food for thought.