Companies must lift the lid on how much money they make through their subsidiaries in poor countries, says Christian Aid.

By lumping their profits into one consolidated bundle it is impossible to work out how much tax multinationals are, or should, be paying, critics say.

The charity has added its voice to that of Dave Hartnett, HM Revenue & Customs permanent secretary, who has warned the issue was on the agenda of the UK and several other governments.

Last week Christian Aid said it has contacted “thousands of its supporters” asking them to encourage multinationals including Marks & Spencer, Rolls-Royce, BT and Barclays to respond to a Christian Aid survey about tax and development. The group has already written to all FTSE 100 companies, asking them whether they would support the introduction of a new, more transparent accounting standard.

Country-by-country report ing would mean “tax anomalies could be more quickly spotted,” the body said.

Unsurprisingly, companies have dug their heels in on the issue. Country-by-country reporting would be a heavy burden in terms of annual reports which already weigh in heavily. However, accountancy standard setters are mulling country-by-country for the mining industry, so companies may have a fight on their hands

Companies can dig in.

But by doing so they condemn the poor to remain poor.

Is that their choice?