03 June, 2017
YouGov's analysis puts the Tories on 310 seats, down from the 330 they went into the election campaign with, and 16 short of a majority.
After an overnight opinion poll indicated the Conservative party's lead was likely to all but disappear, a later survey on voting intentions showed the Tory lead remained intact.
A failure to win the June 8 election with a large majority would weaken May just as formal Brexit talks are due to begin while the loss of her majority in parliament would pitch British politics into turmoil.
According to this latest constituency-by-constituency modelling by YouGov just nine days before the general election, rather than increase the comfortable 17 seat majority she enjoyed, Theresa May is now looking at the humiliating prospect of losing 20 of the 330 seats Conservatives hold and the Labour Party could gain almost 30 seats.
If May fails to win an overall majority, Britain would be thrust into political turmoil: May would be forced to strike a deal with another party to continue governing either as a coalition or a minority government.
More recently we saw the YouGov poll predicting a hung parliament and cable fell 0.5% while the FTSE rallied 0.13%. The financial markets had already pulled down the pound from its recent high around 1.305 against the dollar as recent polls suggested that a lead for Theresa May's Conservative Party is diminishing fast, especially after this month's deadly Manchester attack.
"Then people will have a choice as to who they want to see as leader, who they want to see as prime minister taking this country forward in the future: me or Jeremy Corbyn".
What is the state of play according to other polling companies?
The headline figures certainly stand out given previous assumptions and polling data pointing to the Conservatives securing a majority.
During the European Union referendum campaign it consistently showed that more voters favoured Leave than Remain.
At the last election, the final polls underestimated the Conservatives by four points and overestimated Labour by two points. "Combining the model probabilities and estimated census counts allowed the pollster to produce what it hopes is a fairly accurate estimate of the number of voters in each constituency intending to vote for a party on each day".
Yougov defended their poll, with Stephan Shakespeare of the company saying their model was tested in advance of last year's Brexit referendum and that they always had Leave ahead.