Remain campaigners have warned voters will be hit hard in the pocket if Britain quits the European Union, while the Leave camp has highlighted immigration pressures as the referendum campaign enters its final stages.
Unions warned families face an extra £580 a year bill if the country backs Brexit and retail chiefs said the impact of quitting would be "catastrophic".
David Cameron's former policy guru, meanwhile, claimed the Prime Minister was told four years ago that it was "impossible" for the Government to meet its immigration promises as long as the UK remained in the 28-member bloc.
Research for The Daily Telegraph said the In camp was seven points ahead with 53% of the vote among those who intend to have their say at the ballot box.
But the ORB International study found that when all voters are taken into account, the Remain lead drops to two points on 49%, compared to 47% for Leave.
Exit poll supremo John Curtice, a professor at Strathclyde University, said the possibility of the UK quitting was being underestimated, suggesting a 45% probability was a "sensible" assessment.
Boris Johnson is set to go up against Ruth Davidson in front of an audience of 6,000 voters at the SSE Arena, Wembley.
The leading Vote Leave campaigner, Labour's Gisela Stuart and Conservative Andrea Leadsom will take on the leader of the Scottish Conservatives, London mayor Sadiq Khan and TUC General Secretary Frances O'Grady in the BBC's Great Debate.
Jeremy Corbyn and some of Labour's most senior figures, including former Prime Minister Gordon Brown, are hitting the road in a blitz aimed at winning over wavering party supporters to Remain in the final 48 hours of campaigning ahead of Thursday's vote.
Research by trade union Usdaw puts the increase in prices for families at £580 a year, fuelled by a hit to sterling and new tariffs imposed on imported food, drink and clothing. Stronger In also claimed inflation sparked by Brexit would cause a hike in rail fares.
Former retail bosses, including Tesco's Sir Terry Leahy, Marks and Spencer's Marc Bolland and Sir Justin King from Sainsbury's, issued a price warning.
In an open letter, they said: "We strongly believe that a Brexit will see less money in people's pockets and be catastrophic for millions of ordinary families."
Leave supporter Steve Hilton attacked the promises made by David Cameron over curbing immigration, claiming the premier was told four years ago that it was "impossible" for the Government to meet its targets while Britain remained in the EU.
The Prime Minister's former policy guru said civil servants "directly and explicitly" explained that the pledge to reduce net migration - which last month hit 333,000 - to the tens of thousands would fail.
Just weeks ago, Mr Cameron insisted he stuck by his ''ambition'' to pull the number under 100,000.
Mr Hilton said the premier reaffirmed his commitment to target in the 2015 general election even though he "had been told it was undeliverable".
Writing in The Daily Mail, the Leave campaigner recalled the details of a meeting in the final months of his time as director of strategy.
He said: "We were told, directly and explicitly, that it was impossible for the Government to meet its immigration target as long as we remained members of the EU, which of course insists on the free movement of people within it.
"In the 2015 Conservative manifesto, the Prime Minister reaffirmed his commitment to the immigration target he had been told was undeliverable," he added.
"When I saw that, I assumed this was either because he was certain he could negotiate a solution within the EU, or was assuming we would leave."