However, a new YouGov poll on Wednesday showed a reverse in sentiment, and the Conservatives are now projected to lose as much as 16 seats.
The latest opinion polls ahead of the United Kingdom's general election show a race considerably tighter than was anticipated when campaigning began last month, but with the Conservative Party of Prime Minister Theresa May still holding a healthy lead over Labour.
The Daily Telegraph newspaper's rolling average of the last eight polls put the Conservatives on 44 percent, Labour on 36 percent, the centrist Liberal Democrats on eight percent and the anti-EU UK Independence Party (UKIP) on five percent.
Labour's projected 257 plus minority party seats would add up to 340, creating what would be a minority government of another coalition.
The poll, conducted by YouGov for The Times, is a campaign low for the government.
The currency's drop "is another example of markets not being prepared for a close election, let alone a hung parliament", said Sean Callow, a senior currency strategist at Westpac Banking Corp., the second most-accurate major currencies forecaster in Bloomberg's latest ranking.
May said that while she was ready for negotiations set to start 11 days after the June 8 vote, the Labour leader would "find himself alone and naked in the negotiating chamber of the European Union".
Two years ago, Mr Cameron had a lead of seven points and won an overall majority of just 12.
In a speech on Tuesday in Wolverhampton in central England, home to one of the Conservatives' target seats, the prime minister sought to pivot the debate back to Brexit.
"Generally speaking, the polls that continue to show a large Conservative lead are those who are basing their turnout models on the pattern of turnout in 2015".
"Under-30s love Corbyn but they don't care enough to get off their lazy arses to vote for him", the candidate said.
"Amber Rudd is up next".
May had ruled out any face-to-face debates during the campaign and Corbyn had followed suit, before changing his stance.
May has consistently said she prefers to meet voters on the campaign trail than take part in a line-up of leaders on television.
As her lead shrank, May was forced to backtrack on the policy at an appearance before the media on Monday at which she appeared flustered and irritated when taking questions from reporters.