Cameron made his long awaited speech promising a referendum on continued British membership in the European Union on January 23, and he placed the blame squarely on plate tectonics: ''People are increasingly frustrated that decisions taken further and further away from them mean their living standards are slashed through enforced austerity or their taxes are used to bail out governments on the other side of the continent.''

The ''frustrated'' people in question are English, of course. Hostility to the European Union is mainly an English thing, but that matters a lot in Britain, where 55 million of the kingdom's 65 million people live in England.

The Scottish nationalists seeking separation from England in their own referendum take the opposite tack. They promise the Scottish electorate that leaving Britain would not mean leaving the European Union - although in fact Scotland would probably have to re-apply for membership - because otherwise very few Scottish voters would say ''yes'' to independence.

But the ''Little Englander'' glories in the notion of England being unencumbered by foreign ties and commitments. It's the kind of nationalism that Americans call ''isolationism'', and the phrase is now used to describe strongly nationalist, even xenophobic people on the right of English politics. Those people, always present in significant numbers within Cameron's Conservative Party, have now won the internal party debate.

Every Conservative leader has had to deal with these people. They always managed to contain them in the past, because the European Union is Britain's biggest trading partner, and it is obviously in Britain's interest to belong to the organisation that makes the rules for Europe's ''single market''. What has changed is that the long recession and relatively high immigration of recent years have increased the popularity of the extreme right in England.

That doesn't mean that populist demagogues and neo-fascists are about to win power in Britain. Far from it: they'd be lucky to get 10 per cent of the vote. But it does mean that the Conservatives are losing their more right-wing supporters to the anti-EU, anti-immigration United Kingdom Independence Party.

UKIP could never win an election in Britain, but it could easily steal enough votes from the Conservatives to make them lose the next election. So there has been mounting panic in the Conservative Party, and not just among its instinctively anti-EU members.

Cameron's promise of a referendum on EU membership is first and foremost an attempt to steal UKIP's thunder and win back the defecting Conservative voters. He doesn't really want to leave the EU, but he really does want to win the election that is due in 2015.

His reluctance to be the man who took Britain out of the EU was evident in the way he hedged around his referendum promise. The referendum would not take place until after the next election, and only if the Conservative Party won enough seats in 2015 to form a government on its own. (Its current coalition partner, the Liberal Democratic Party, opposes the whole idea).

Cameron says he will spend the next two years renegotiating the terms of Britain's EU membership to ''repatriate'' many powers from Brussels to London, and to make various changes in the way the EU is run. Then, if he is satisfied with the outcome, he will support EU membership in the election and in the subsequent referendum, which will be held by 2017. But he had no satisfactory answer to the hard questions that followed his speech.

What if the 26 other EU members choose not to waste months in talks on changing Britain's relationship with the EU? What if they do negotiate but refuse to tie themselves up in knots just to ease Cameron's local political problems? Would he support continued EU membership in the promised referendum if he didn't have a ''new deal'' to offer the voters? He simply wouldn't answer those questions.

So for the next four years, all those foreign companies that have been using Britain as a convenient, English-speaking centre to produce goods and services for the European market will be re-thinking their investment strategies. If Britain may leave the EU by 2017, is this really the right place to put their money?

How did an allegedly grown-up country talk itself into this position? It's an attitude that was summed up in an apocryphal English newspaper headline of the 1930s: ''Fog in (the English) Channel; Continent Cut Off.''

Gwynne Dyer is an independent journalist whose articles are published in 45 countries.