It is dangerous to stand in the way of politicians rushing for the moral high ground, as British multinationals operating in Zimbabwe have discovered in the past week.

As pressure on Robert Mugabe's regime has increased, politicians have questioned the role of foreign companies operating in Zimbabwe.

The Prime Minister suggested they “reconsider” their position while the Africa Minister hinted that British companies could be “pressured” to quit Zimbabwe as part of a package of tougher sanctions.

This language spooked a number of companies, which called the Foreign Office to seek clarification on what they should be doing. They were told not to worry and to keep on with business as usual.

Not for the first time political rhetoric has run ahead of diplomatic reality. The current sanctions on Zimbabwe extend only to a ban on arms sales and the travel plans of Mugabe's henchmen.

There are almost no limits on companies that want to do business in Zimbabwe and a number have expressed annoyance that they have been treated like collaborators with the Mugabe regime for simply following the rules.

This is understandable but it is also a rather naive view of the situation engulfing Zimbabwe. Hiding behind the Foreign Office's by-the-book advice should not absolve companies from their duty to question whether it is right to do business in Zimbabwe.

Tesco has already decided that it is inappropriate to continue sourcing food from Zimbabwe and companies with brands to protect, such as Barclays, must be calculating whether staying in the country makes good sense. Nobody wants to be seen to be supporting a tyrant.

Then there are other companies such as Rio Tinto, the miner, which has effectively mothballed operations until Mugabe has been ousted. This contrasts with Anglo American, which is ploughing ahead with its $400 million investment in the country.

Ultimately, it is for the boards of these companies to decide which of these strategies is appropriate for Zimbabwe: stay, go or expand. They would do well to remember, however, that when politicians run for the moral high ground it is usually because the rest of the population has already camped out there.

Those still at base camp will come under fire even if they are following the letter of the law.

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