Twenty years after the Berlin Wall came down, there is still a term for the psychological differences between the Ossis, the Easterners, and the Wessis, the Westerners. It is known as the Mauer im Kopf; the wall in the head. As European leaders gather with their entourages in Berlin to commemorate the anniversary of German reunification, the wall in their heads is very much intact. Behind it they are concealing the identities of their candidates for two new important posts.

The ratification of the Treaty of Lisbon means that, when it comes into law on December 1, the posts of the president of the European Council and the European Union high representative for foreign affairs will be created. In Berlin on Monday, freedom will be celebrated by the toppling of 1,000 eight foot foam domino tiles along the route of the old wall, U2 will play a free concert that is proving so popular a new wall is being built to keep people out. Meanwhile, somewhere else in the city, Angela Merkel, the first Chancellor from the east of the united Germany, will tear the European leaders away from the festivities to parcel out the new prizes.

The man ostensibly in charge of the process is the final incumbent of the European Union’s rotating presidency: Fredrik Reinfeldt, the Swedish Prime Minister. Mr Reinfeldt has a clear choice. He could run the process openly and transparently, encouraging all those with a vote to identify two candidates for each post and spell out why they are the right people for the job. Or he could follow the ingrained habit of European Union proceedings and preside over a secret conversation that yields decisions from which the European people are again excluded.

“Sunlight,” said the great American Supreme Court judge Louis Brandeis, “is the best disinfectant.” Perhaps Mr Reinfeldt will not see that closing the doors, following fast on the anti-democratic passage of the Lisbon treaty, will damage the popular idea of Europe. Perhaps the principal discutants, Angela Merkel and Nicolas Sarkozy, will decide the winners and then attempt to corral their colleagues into yielding.

But there is nothing to stop anyone else from declaring their hand in public. The Prime Minister has told us that the British Government will be backing Tony Blair as its candidate for the post of president and the Foreign Secretary, David Miliband, has added his support. We do not yet know whether Gordon Brown has anyone in mind for the foreign minister’s job. Mr Brown should declare his two candidates for each post, say why he has chosen them and then press other European leaders to do the same.

But, wrapped up in the identities of the candidates is a very serious constitutional question about the type of jobs that are being created. These are posts that may well be defined by the incumbent, rather than bound by a tightly worded job description. Is the president of the Council a job for someone who, in Mr Miliband’s highly revealing phrase, can stop the traffic in the power capitals of the world? Is this, in other words, a job for someone who is the principal representative of European nations? Is the president the person to whom Beijing and Washington should look in their dealings with the European Union? If so, that candidate needs to be someone of genuine international standing.

There is also a much better case for precisely the opposite, for a less exalted but effectual bureaucrat capable of smoothing the operation of 27 national leaders but usurping none of their authority in the process. It is not at all clear what the European elite is looking for, and without any clarity on the nature of the post it is impossible to assess the virtues of the candidates. For those of us not in Berlin, it is impossible anyway, unless our leaders deign to let us know what they think.