A major impact has been to require States to protect the Convention Rights of ALL individuals and not just powerful majorities. Article 1 states clearly:
There are no categories of individuals who are to be denied Convention rights no matter who they are or what they have done or may have done.
The illustrative case of Bellinger v Bellinger  UKHL 21 was concerned with the rights of transsexuals. In an 'over-simplified and question-begging form' the issue was whether a person could change the sex with which he or she was born? More specifically, was Mrs Elizabeth Bellinger, validly married to Mr Michael Bellinger since, of course, marriage was confined to persons of opposite sex.
The leading speech was that of Lord Nicholls of Birkenhead which is a masterful analysis of the development of the law relating to transsexualism and marriage. His Lordship noted
that the issue had been before the European Court of Human Rights (E Ct HR) on several occasions - Rees v United Kingdom (1986) 9 EHRR 56, Cossey v United Kingdom (1990) 13 EHRR 622, and Sheffield and Horsham v United Kingdom (1998) 27 EHRR 163 - culminating in Goodwin v United Kingdom (2002) 35 EHRR 18. It was in Goodwin where the E Ct HR finally took the view that the UK's 'margin of appreciation' could no longer extend to refusing to give legal recognition to gender reassignment and, in Goodwin, the UK was held to be in breach of Articles 8 (Respect for Private and Family Life) and 12 (Right to marry).
In December 2002, the British government announced an intention to bring forward legislation to allow transsexual people who can demonstrate they have taken decisive steps towards living fully and permanently in the acquired gender to marry in that gender. There was also recognition by the British government that domestic law was incompatible with articles 8 and 12 of the Convention.
The eventual outcome was the Gender Recognition Act 2004. The Bellinger case also demonstrates the importance of looking at the European Convention as a 'living instrument' rather than as a document locked into the attitudes or mores of the post-war world of the 1950s. The 'living instrument' viewpoint, which is not favoured by some politicians, may be traced back to Tyrer v UK 1978 (Concerning corporal punishment in the Isle of Man). Even if it is arguable that a change to our domestic law would have eventually come, the living instrument viewpoint spurred on this important change. (For more on this approach see the article here).
The Bellinger case is also an important authority as to when the courts will make a 'declaration of incompatibility' in relation to an Act of Parliament. Such declarations are possible under the Human Rights Act 1998 s.4 (HRA) but they do NOT instantly alter the law. Change must be made by Parliament and the HRA provides a 'fast track' method for doing that.
Lord Nicholls said (paras. 53 to 55) that non-recognition of gender reassignment was not compatible with the articles 8 and 12. In Goodwin, the European Court of HR had held that to be so. His Lordship was not persuaded by argument that making the declaration of incompatibility would serve no useful purpose. At para 55 he said:
'If a provision of primary legislation is shown to be incompatible with a Convention right the court, in the exercise of its discretion, may make a declaration of incompatibility under section 4 of the Human Rights Act 1998. In exercising this discretion the court will have regard to all the circumstances. In the present case the government has not sought to question the decision of the European Court of Human Rights in Goodwin. Indeed, it is committed to giving effect to that decision. Nevertheless, when proceedings are already before the House, it is desirable that in a case of such sensitivity this House, as the court of final appeal in this country, should formally record that the present state of statute law is incompatible with the Convention. I would therefore make a declaration of incompatibility as sought ....'
In 2004, in a separate development, Parliament also enacted the Civil Partnership Act permitting civil partnerships between same sex couples. Article 12 of the E Conv HR refers to 'men and women' having the right to marry eachother and in Rees v UK (1987) 9 EHRR 56, the E Ct HR said that the right to marry refers to the traditional marriage between persons of opposite biological sex. It followed that there was no obligation on States to recognise in law marriages or civil partnerships between homosexuals - see Wilkinson v Kitzinger  EWHC 2022 paras 44-48.
To similar effect is Schalk and Kopf v Austria 2010. though here the court was cautious to note the contemporary nature of its judgment in relation to Article 12 but held that, as matters stand, the question of whether or not to allow same-sex marriage is left to regulation by the national law of the Contracting State.' On this, see the interesting discussion by barrister Andrew Commins in Family Law Week.
The Civil Partnerships Act was clear recognition by Parliament of a development across Europe to recognise in law the commitment made to each other by persons of the opposite sex. Furthermore, the Marriage (Same Sex Couples) Bill is now making its way through Parliament - discussed in the post of 5th February 2013.