British Prime Minister David Cameron is launching the first full week in a 10-week campaign on a referendum on whether the country should remain a member of the European Union with a huge publicity blitz.
Government ministers will be attending rallies across Britain to urge voters to say "yes" to continued EU membership when they go to the ballots on June 23.
The opposition Labour Party is also telling its supporters to do the same. And US President Barack Obama is arriving in London on Thursday, carrying the message that Britain is better off inside the EU.
Yet the latest opinion polls indicate that British voters are increasingly being won over by arguments for leaving the EU. Support for getting out now stands at 45 per cent, three points ahead of the "remain" camp.
"We expected a tightening of the race, and the current figures indicate that our task of explaining what we believe to be right for our country is far from over," Britain's Europe Minister David Lidington told The Straits Times, speaking on the margins of a European security conference.
Still, his ministerial colleagues are rattled by evidence that their carefully planned "remain" campaign is failing.
Mr Cameron, who planned for this referendum for years, initially hoped to retain the upper hand by negotiating a special deal with the EU exempting Britain from some key EU obligations.
That deal, concluded in February after months of intensive talks, allowed Mr Cameron to claim that Britain now "had the best of both worlds": It could continue enjoying the free trade and investment advantages offered by EU membership, but set aside unpopular obligations such as allowing any EU citizen coming to the UK access to the country's welfare funds.
Cabinet ministers in London hope that, ultimately, voters will opt for the status quo, largely because the alternatives are too risky for Britain's economy. But all acknowledge that the positive case for the EU has proven far harder to make...
However, the tactic backfired as voters found the argument far too abstract and complicated. The deal is no longer even mentioned on the hustings.
The Labour Party is not much help either. Mr Jeremy Corbyn, its far-left leader, waited until last week before delivering his first formal speech in favour of staying in Europe, but then undermined his case by arguing that Europe should admit many more refugees from the Middle East and Africa - hardly the sort of argument likely to convince ordinary Britons that they should stay in the EU.
Meanwhile, the "Brexit" campaigners led by Mr Boris Johnson, the popular mayor of London, have proven much more adept at arguing their case. They are accusing the government of spreading unnecessary fear about the consequences of leaving the EU, although they cannot offer a plausible alternative that will not hurt the country's economic prosperity.
However, the biggest problem for the "yes" camp is the Prime Minister's fading popularity. Mr Cameron's image suffered after recent revelations contained in the so-called "Panama Papers" which indicated that his father had set up and run an offshore investment fund. The fund was legal and all its beneficiaries paid their taxes.
Still, the row that ensued forced Mr Cameron to become the first British prime minister ever to publish his tax returns, and cast him as part of the international rich set rather than as a man of the people.
The risk is, therefore, that people may be tempted to vote "no" to the EU just to hit at the Prime Minister. Opinion polls indicate that Labour's Mr Corbyn, hitherto dismissed as unelectable, is now more popular than Mr Cameron.
Mr Cameron hopes that Mr Obama's visit to Britain this week will strengthen his hand. Mr Obama has made no secret of his view that Britain's membership of the EU gave America "much greater confidence about the strength of the trans-Atlantic union".
However, Mr Johnson has dismissed Mr Obama's planned intervention as "a piece of outrageous and exorbitant hypocrisy", claiming that Americans would never accept the sort of restrictions on their sovereignty that the EU demands from its members. This may well resonate with ordinary Brits.
Cabinet ministers in London hope that, ultimately, voters will opt for the status quo, largely because the alternatives are too risky for Britain's economy.
But all acknowledge that the positive case for the EU has proven far harder to make, and that the British Prime Minister's political career will end abruptly should he fail to secure a "yes" vote in June.
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