On December 31st, the Minister for Finance Mr McCreevy and Dr Michael Somers, chief executive of the National Treasury Management Agency (NTMA), will appear in public together when the NTMA publishes its end-year figures.

No doubt by then the Department of the Finance and the NTMA will hold the same view on the Exchequer outcome for 1998. At the moment, despite attempts by the Minister and the Department to play the affair down, differences remain.

The key point made by Dr Somers in his interview with The Irish Times, published yesterday, was quite straighforward. The latest official figures show that the surplus of Exchequer revenue over spending in the first 11 months of the year stands at £1.9 billion. In his Budget speech, however, the Minister said that the closing surplus at the end of the year would be £668 million. For the surplus to fall so sharply in one month, the Exchequer will have to spend a huge amount more money than it takes in during December. How can this happen?

The Department said that, in the light of the November figures, which were published after the Budget had gone to the printers, it was revising up its end-year Exchequer surplus forecast to £750 million. This still leaves a large gap between the end-November out-turn and the projected end-year figure.

Speaking in Vienna at the EU Summit, Mr McCreevy pointed out that December was normally a high-spending month and that some £2.1 billion could be spent this month - an exceptionally high amount. Apparently the Department is planning a number of major payments this month, although the precise details are unclear.

Some £1 billion in tax revenues is due into the Exchequer in December, so if the high spending level pointed to is achieved, much of the end-November surplus will, indeed, be wiped out. However, such a monthly out-turn would be unusual - last December, for example, spending exceeded revenue by around £200 million.

Whatever the precise out-turn, there will now be a close focus on the end-of-year figures. The size of the surplus will determine how fast the national debt falls this year. The Department is sticking with its end-year target of £29.7 billion, despite Dr Somers's estimate that at end-November it was just £28.3 billion.

That such a difference of view about the Exchequer finances should break out in public is most unusual and indicates the tensions that remain between the NTMA and the Department, which have lingered since many in the Department objected to the establishment of the agency in the first place. However, the other comments made by Dr Somers also deserve attention.

He has pointed to the difficult the NTMA is having in modernising the Government bond dealing system. The Central Bank and the Department both say they are participating in moves to change the system but clearly Dr Somers wants speedier reform.

And, with his experience in the markets, he should be listened to when he criticises the £40 million the Government has put aside to pay bankers and advisers to float Telecom Eireann as excessive.