The international tax wars are continuing, with unpredictable consequences. The amount of tax paid by multinationals is now a live political issue and nobody disputes that change is on the way. The only question is how fundamental it will be.

One of the key things to watch in the weeks ahead will be what happens on so-called country-by-country reporting, a proposal that multinationals should report on their turnover and profits in each market. This would go some way to unpicking the mysteries of how money is shifted around the globe, often with the effect of reducing the tax paid by US multinationals on profits earned outside their home market to very low levels.

But how exactly will it work? Reports this week said that the EU Commission would propose next month that companies with turnovers in excess of €750 million would report each year on their turnover and profit in each market, posting the details on their website. This is a follow-up to new OECD proposals on the issue, with the US also planning to publish new reporting proposals by mid-year.

Aspects of this proposed plan have caused some disappointment among tax justice campaigners. In a statement, Christian Aid particularly objected to one aspect of the proposals – at least the leaked version thereof. It said reports that companies would not have to declare their financial figures for each individual market outside the EU would still leave it unclear what was being squirrelled away in tax havens.

But while the tax justice lobby may feel that this does not go far enough, the suggestions from the US and from the multinationals is that the EU Commission proposals may go too far. The big companies do appear willing to provide data to the tax authorities in each individual country, information they would then share. However, the amount of information which will actually be made public is likely to be a big issue, with the firms involved arguing that much of it will be commercially sensitive. We will give the data to the Revenue authorities, they will argue, but we don’t want it published.

This could yet get messy and will play into a general mood in Washington that the EU Commission is out to " bash" US companies. And that is even before the final decision relating to Ireland's treatment of Apple is published.