British voters will go to the polls this month to decide whether their country should remain in the European Union (EU). As the date, June 23, approaches, the "leave" and "remain" campaigns are dialling up the volume, with claims and counterclaims flying, many with only a tenuous relationship to facts.

According to those who favour leaving the bloc, Britain is the victim of faceless, highly compensated bureaucrats in Brussels who meet in secret and churn out off-the-wall regulations costing businesses billions of pounds a year. They say British citizens are subjected to taxes and other measures by a supposedly unaccountable European Parliament, while Britain as a whole sends far more money each year to Brussels than it gets back. Above all, perhaps, they say Britain is virtually powerless to stop the influx of migrants - more than 300,000 arrived last year.

Those who support remaining in the bloc play down those issues, focusing on what a seemingly inexhaustible supply of government officials, economists, bankers and business executives call the dire consequences of leaving: a weakened currency, job losses, slower growth, depressed trade, the end of London's status as a world financial capital and a loss of influence in European affairs.

Immigrants, just over half from EU member states, give the economy energy, youth and creativity, they say, contributing to the economic vitality that makes multicultural London the envy of the world.

Some have called the campaign the "Trumpification of politics" in Britain. With dubious assertions flying around, the debate can appear unseemly. Here are a few of the claims, and some judgments about their veracity:

THE 'LEAVE' SIDE SAYS:Britain sends £350 million a week to the European Union

According to the UK Statistics Authority, Britain owed a gross contribution to the European Union of £19.1 billion (S$37.3 billion) in 2014. That's £367 million a week. However, Britain gets an immediate rebate off the top, negotiated in 1984 by Prime Minister Margaret Thatcher, so it actually sent £14.7 billion, or £283 million a week, in 2014. Brussels also returns money to Britain for sectors including agriculture, regional development, science and universities. The actual net contribution from Britain is about £9.9 billion a year.

That's about £190 million a week, a little more than half of what Vote Leave claims. It is roughly 0.5 per cent of British gross domestic product (GDP) and around 1.3 per cent of the current British Budget of about £770 billion.

THE 'REMAIN' SIDE SAYS: Three million jobs in Britain depend on membership in the European Union

Doubtful. The original study simply said that "3.45 million jobs depend upon exports to the EU". But there is no question that Britain would continue to export to the EU and elsewhere even if it left the bloc. Trade might be more complicated and expensive outside the single market, but the United States and China, to name just two countries, do a lot of trade with the EU without being members.

'LEAVE' SAYS Britain has lost 75 per cent of the 131 cases brought against it before the European Court of Justice, and thus has lost a crucial element of sovereignty

True, at least the first part. But the European Commission, for example, brings only cases it thinks it can win. And 91 of the cases were brought by the commission because of Britain's failure to put in effect European law, as it is obligated to do. France, by comparison, has lost 90 per cent of the last 50 cases brought to the court.

'REMAIN' SAYS: A British exit would cost each household £4,300 a year by 2030 It depends on your assumptions, but some loss of national income is inevitable.

Those who favour staying in the bloc cite a study by the British Treasury that looked at three alternatives to EU membership. For comparison, the Treasury chose one, a negotiated bilateral agreement with the European Union, like the ones the bloc has with Switzerland and Norway.

The figure cited represents an annual loss of GDP per household after 15 years, estimating 6.2 per cent lower growth nationally by 2030. But this does not translate to cash, and it is based on numerous assumptions.

And, of course, there is no way of knowing what kind of relationship Britain would have with the EU after a so-called Brexit. Michael Gove, a leader of the "leave" campaign, has said Britain would not want a bilateral deal that required it to accept freedom of movement and labour, so it would choose a simpler World Trade Organisation relationship with the European Union, like the ones held by Brazil and Russia. That kind of relationship, the Treasury suggests, would mean a bigger annual loss of GDP per household by 2030 of £5,200.

Still, every alternative the Treasury examined would reduce GDP, a position accepted by most economists.

'LEAVE' SAYS: 'Uncontrolled migration' imposes 'huge unfunded pressures on the NHS and on other public services', said Mr Boris Johnson, the former mayor of London, referring to the National Health Service

Pressures, absolutely. Unfunded, not exactly.

An estimated 85 per cent of non-British EU citizens in Britain are economically active, contributing a net £22 billion to the Treasury.

But is immigration "uncontrolled"?

Citizens of EU countries have the right to live and work in any member state. But Britain, which is not a part of the Schengen zone of largely passport-free travel, has the right to check everyone at its borders and can deny entry for a host of reasons.

Net annual migration to Britain rose slightly, to 333,000, last year, according to the Office for National Statistics. EU citizens made up 55 per cent of that figure (184,000).

Britons migrate to other EU countries too, especially retirees who can live more cheaply elsewhere and still get free medical benefits. About 300,000 Britons left the country last year - more than the 184,000 EU citizens who moved to Britain. About one million Britons live in Spain, about 255,000 in Ireland and about 175,000 in France.

Britain has taken substantial measures to try to reduce immigration, raising the skills requirements for non-EU citizens and reducing incentives for EU citizens coming into the country for low-paid jobs.

As for strains that immigration puts on public services, there is no question.

Rapid population increases in some cities and towns across Britain have put pressure on hospitals, housing, schools and policing. Since the 2000s, the East Midlands and Northern England have experienced the biggest percentage increases in non-British-born populations.

Boston, a town of 67,000 in the Midlands, experienced a sixfold increase in foreign-born residents, driving many people out of town for doctors' appointments and emergencies because practitioners in town were overstretched. At one point, the town's council arranged for children to be taken by taxi to schools in neighbouring towns because there were not enough places locally. The crisis eased somewhat as increased tax revenue, a result of the growing population, helped finance new schools and hospitals.

A 2011 government study found that national spending per person on healthcare attributed to foreigners, who are mostly young adults, was lower than for Britons; spending on education was higher, but outlays for government aid for both groups were comparable.

But immigrants also contribute substantially to the National Health Service, which relies on them to function.

Immigrants make up at least 20 per cent of the service's workforce. There is a chronic shortage of nurses, radiologists and emergency medicine specialists, among others, according to a government list of occupation shortages. About a third of nursing shifts covered by agency staff hired by the National Health Service are immigrants with temporary visas.

'REMAIN' SAYS: A British exit from the bloc would throw the country into recession and result in a loss of 500,000 jobs, lower wages and lower house prices. The cost of vacations would also go up by an average of £230 , Prime Minister David Cameron says

The macroeconomic claims cite a Treasury study looking at the short-term economic effects of leaving the European Union, modelled on economic assumptions about the level of "shock" a departure would bring - regular or severe - and on estimates for a weaker pound.

Economists from both sides of the membership debate agree that there would be a short-term economic shock and slower growth. But estimates of how much vary, and the Treasury's numbers are considered a bit pessimistic, but generally correct.

As for more expensive vacations, Mr Cameron points to the likelihood of a weaker pound, coupled with increased airfares and higher cellphone roaming charges. By 2018, he says, the cost for four people to take a nine-night vacation in Spain would be £225 more. For two weeks in the United States, it would be £620 more.

Again, there are many assumptions. But those who favour remaining in the EU hope that voters will take note of the specific figures, even if based on unprovable estimates and judgments about the future.

'LEAVE' SAYS: The British economy is choking on a mass of regulations from Brussels

To some extent, the truth is in the eye of the beholder on this one. The House of Commons Library has warned that "there is no totally accurate, rational or useful way of calculating the percentage of national laws based on or influenced by the European Union", concluding that it is "possible to justify any measure between 15 per cent and 50 per cent or thereabouts".

Britain has the second-least regulated economy in Europe, after the Netherlands, according to the Organisation for Economic Cooperation and Development, and the "remain" campaign says many EU regulations are aimed at maintaining market competition and, on balance, save Britain about US$30 billion (S$40.7 billion) a year.

'LEAVE' SAYS: Not only does the EU rule on the curvature of bananas, it will not allow them to be sold in bunches larger than three, Mr Johnson said

There is no rule on how, or how many, bananas may be sold.

Mr Johnson has also said that after leaving the union, "UK asparagus will be just as sprouting, just as delicious, in fact even better!"

The proof of the pudding is in the eating.

NEW YORK TIMES

•Additional reporting by Kimiko de Freytas-Tamura