General election 2015: Labour and the Tories neck-and-neck to be largest party, says latest academic prediction

Psephologist Lewis Baston’s model shows the two largest parties each getting 272 seats across the UK, a 30-seat fall for Labour since January.

The result would likely see a hung parliament in which an SNP-Labour bloc could command a majority ahead of parties willing to enter coalition deals with the Tories.

Such an arrangement would likely lead to Ed Miliband becoming prime minister.

The academic said Labour’s lead has dwindled because so many of the party's Scottish seats are predicted to change hands to the Scottish National Party.

“Today it seems like charity to predict victory for any non-SNP candidate in any seat in Scotland with the exception of Orkney and Shetland,” Mr Baston said.

The academic, who works for the group Democratic Audit, said Labour could be wiped out north of the border.

The suggestion chimes with a similar projection by the Electoral Calculus website.

According to that calculation, the figures in the latest Scotland poll by the firm TNS would give the SNP 57 of Scotland's 59 seats.

Labour and the Liberal Democrats would be left with a single MP each were the results of the poll repeated on polling day with a uniform swing.

The survey saw the SNP rise 2% and Jim Murphy’s party fall 2% since the last study by the same pollster.