This is while May called the snap election in an effort to reinforce her negotiation position on Britain's exit from the European Union, to win more time to deal with the impact of the separation and to strengthen her grip on the Conservative Party.
But if she does not handsomely beat the 12-seat majority her predecessor David Cameron won in 2015, her electoral gamble will have failed and her authority could be undermined just as she enters formal Brexit negotiations.
The poll put the Conservatives on 46 percent and Labour on 32 percent, little changed from the previous ICM poll on May 22 which put the Conservatives on 47 percent and Labour on 33 percent.
The Opinium poll, taken after Monday's suicide bombing in Manchester, also found May's approval ratings had slumped from plus-17 to plus-11 over the week, while Mr Corbyn's rose from minus-18 to minus-11.More news: Gay player wants Margaret Court stripped of Aussie stadium title
More news: Manchester attack: United States paper leaks images of explosive device
More news: (CVX) is American Investment Services Inc.'s 2nd Largest Position
"We've put into the policy now some additional reassurance because of the scaremongering of Labour after the manifesto was published, further reassurance that people will not lose their home, they will not lose all of their savings". Mr Corbyn's 10-point lead among this age group was up from eight points in the first days after the election was announced.
Although the results are less dramatic than Friday's YouGov survey, which found the Conservative advantage squeezed to just five points, they tally with the trend in a number of polls which have shown Labour gaining on the Tories after having begun the election race as much as 25 points adrift.
Moreover, ComRes, which carried out an online poll of 2,024 on May 24-26, said the lead of the ruling Tory party had dropped to 12 percentage points from 18 percentage points in a comparable poll on May 13.
Joint Downing Street Chief of Staff, Nick Timothy, left, reportedly insisted on the social care reform proposals in the Tory manifesto against the wishes of senior colleagues.