Blackburn v Attorney-General  2 All ER 1380
LORD DENNING MR: In this case Mr Blackburn - as he has done before - has shown eternal vigilance in support of the law. This time he is concerned about the application of Her Majesty's government to join the Common Market and to sign the Treaty of Rome. He brings two actions against the Attorney General, in which he seeks declarations to the effect that, by signing the Treaty of Rome, Her Majesty's government will surrender in part the sovereignty of the Crown in Parliament and will surrender it for ever. He says that in so doing the government will be acting in breach of the law. The Attorney General has applied to strike out the statements of claim on the ground that they disclose no reasonable cause of action. The master and the judge have struck them out. Mr Blackburn, with our leave, appeals to this court. He thinks it is important to clear the air.
Much of what Mr Blackburn says is quite correct. It does appear that if this country should go into the Common Market and sign the Treaty of Rome, it means that we will have taken a step which is irreversible. The sovereignty of these islands will thenceforward be limited. It will not be ours alone but will be shared with others. Mr Blackburn referred us to a decision by the European Court of Justice, Costa v ENEL in February 1964, in which the court in its judgment said: "the member-States, albeit within limited spheres, have restricted their sovereign rights and created a body of law applicable both to their nationals and to themselves".
Mr Blackburn points out that many regulations made by the European Economic Community will become automatically binding on the people of this country; and that all the courts of this country, including the House of Lords, will have to follow the decisions of the European Court in certain defined respects, such as the construction of the treaty.
I will assume that Mr Blackburn is right in what he says on those matters. Nevertheless, I do not think these courts can entertain these actions. Negotiations are still in progress for us to join the Common Market. No agreement has been reached. No treaty has been signed. Even if a treaty is signed, it is elementary that these courts take no notice of treaties as such. We take no notice of treaties until they are embodied in laws enacted by Parliament, and then only to the extent that Parliament tells us. That was settled in a case about a treaty between the Queen of England and the Emperor of China. It is Rustomjee v R. Lord Coleridge CJ said ((1876) 2 QBD at 74):
"She [ie the Queen] acted throughout the making of the treaty and in relation to each and every of its stipulations in her sovereign character, and by her own inherent authority; and, as in making the treaty, so in performing the treaty, she is beyond the control of municipal law, and her acts are not to be examined in her own Courts".
Mr Blackburn acknowledged the general principle, but he urged that this proposed treaty is in a category by itself, in that it diminishes the sovereignty of Parliament over the people of this country. I cannot accept the distinction. The general principle applies to this treaty as to any other. The treaty-making power of this country rests not in the courts, but in the Crown; that is, Her Majesty acting on the advice of her Ministers. When her Ministers negotiate and sign a treaty, even a treaty of such paramount importance as this proposed one, they act on behalf of the country as a whole. They exercise the prerogative of the Crown. Their action in so doing cannot be challenged or questioned in these courts.
Mr Blackburn takes a second point. He says that, if Parliament should implement the treaty by passing an Act of Parliament for this purpose, it will seek to do the impossible. It will seek to bind its successors. According to the treaty, once it is signed, we are committed to it irrevocably. Once in the Common Market, we cannot withdraw from it. No Parliament can commit us, says Mr Blackburn, to that extent. He prays in aid the principle that no Parliament can bind its successors, and that any Parliament can reverse any previous enactment....
We have all been brought up to believe that, in legal theory, one Parliament cannot bind another and that no Act is irreversible. But legal theory does not always march alongside political reality. Take the Statute of Westminster 1931, which takes away the power of Parliament to legislate for the dominions. Can anyone imagine that Parliament could or would reverse that statute? Take the Acts which have granted independence to the dominions and territories overseas. Can anyone imagine that Parliament could or would reverse those laws and take away their independence? Most clearly not. Freedom once given cannot be taken away. Legal theory must give way to practical politics.....
What are the realities here? If Her Majesty's Ministers sign this treaty and Parliament enacts provisions to implement it, I do not envisage that Parliament would afterwards go back on it and try to withdraw from it. But, if Parliament should do so, then I say we will consider that event when it happens. We will then say whether Parliament can lawfully do it or not.
Both sides referred us to the valuable article by Professor H W R Wade in the Cambridge Law Journal ([1954-55] CLJ at p 196) in which he said that 'sovereignty is a political fact for which no purely legal authority can be constituted'. That is true. We must wait to see what happens before we pronounce on sovereignty in the Common Market.
So, whilst in theory Mr Blackburn is quite right in saying that no Parliament can bind another, and that any Parliament can reverse what a previous Parliament has done, nevertheless so far as this court is concerned, I think we will wait until that day comes. We will not pronounce on it today.
SALMON LJ: Whilst I recognise the undoubted sincerity of Mr Blackburn's views, I deprecate litigation the purpose of which is to influence political decisions. Such decisions have nothing to do with these courts. These courts are concerned only with the effect of such decisions if and when they have been implemented by legislation. Nor have the courts any power to interfere with the treaty-making power of the Sovereign. As to Parliament, in the present state of the law, it can enact, amend and repeal any legislation it pleases. The sole power of the courts is to decide and enforce what is the law and not what it should be - now, or in the future.
I agree that this appeal should be dismissed.
STAMP LJ: I agree that the appeal should be dismissed; but I would express no view whatsoever on the legal implications of this country becoming a party to the Treaty of Rome. In the way Mr Blackburn put it I think he confused the division of the powers of the Crown, Parliament and the courts. The Crown enters into treaties; Parliament enacts laws; and it is the duty of this court in proper cases to interpret those laws when made; but it is no part of this court's function or duty to make declarations in general terms regarding the powers of Parliament, more particularly where the circumstances in which the court is asked to intervene are purely hypothetical. Nor ought this court at the suit of one of Her Majesty's subjects to make declarations regarding the undoubted prerogative power of the Crown to enter into treaties.