The Tories are losing ground to Labour according to a new poll
This showed Mrs May's lead had fallen sharply from a lead of 12 percentage points in the previous Survation poll published on May 21.
The new poll shows support for the Conservatives at 40 percent, down six percentage points, with Labour on 39 percent, up five points.
The online poll of 1,049 people was carried out on June 3.
Two other polls showed the Tory lead slipping, down to seven points with Opinium and four points with YouGov.
However other polls released showed the Tories had little cause for concern.
The ComRes poll put the Conservatives on 47 points and Labour on 35, a huge 12 point lead.
And YouGov's projection indicated a 14-seat majority for the Tories.
Despite this large lead, the ComRes poll revealed a signifant many more people believe Jeremy Corbyn has better policies for "people like me and my family" than Theresa May.
This section saw Labour on 44 and the Tories on 38.
It comes after a YouGov election model released earlier today estimated the Tories will win 308 seats, 18 short of a 326-seat majority.
Labour are estimated to take 261 seats, up from 257 on Friday, increasing the possibility of a hung parliament.
Polls taken before the snap election was called by Mrs May indicated her party had a 20 point lead. All pollster are now indicating this has been cut dramatically.
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However, Mrs May has repeated dismissed the apparent Labour surge, claiming on several occasions: "The only poll that counts is the one taking place on June 8."
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Pollsters have defended the varied nature of their results.
Ben Lauderdale, who helped to create YouGov's projection system, said: “None of us are stupid, none of us are crazy, we all may be wrong in the end or some of us may be wrong, but it's just a difficult problem.
“The question is what is the alternative? It's not clear there is one.”
He explained the way polls utilised expected voter turnout resulted in discrepancies across different companies.
He said: “The difference in the polls in this election is easy to understand – it is almost wholly to do with how pollsters treat turnout.
"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. Those that show smaller leads are basing turnout on how likely people say they are to vote."
This is a developing story. Check back throughout the evening as more poll results are announced.