Politicians are criss-crossing the country wooing voters ahead of the election in 27 days’ time. But in more than half of seats the result is already known, according to new analysis of safe seats. More than 25million live in constituencies where the result can already be predicted, because one party is so far ahead. There are 650 seats up for grabs on May 7, with Labour and the Tories needing more than half to secure a majority. However, the Electoral Reform Society claims the result in 364 seats can be called now, based on current polls and how ‘safe’ they were in 2010. Scroll down for video . Some 70 per cent of seats in the East of England are considered safe, compared to 10 per cent in Scotland, where the SNP is expected to make sweeping gains . Of 303 Tory seats, 186 are considered safe while 151 of Labour’s 257 constituencies are not expected to change hands. The Lib Dems are defending 56 seats, of which only seven are considered safe, after a dramatic collapse in their poll ratings since joining the coalition with the Tories. Some parts of the country are more likely to play a role in deciding the outcome of the election than others. For example, 70 per cent of seats in the East of England are considered safe, compared to 10 per cent in Scotland, where the SNP is expected to make sweeping gains. The ERS has produced a new online tool for voters to see if they live in an area where the election result will be decided. It is campaigning for a change to the voting system, arguing that First Past The Post, where the winning candidate just needs to get the most votes, fails to take account of the changing face of British politics. Of 303 Tory seats, 186 are considered safe while 151 of Labour’s 257 constituencies are not expected to change hands.The Lib Dems are defending 56 seats, of which only seven are considered safe, after a dramatic collapse in their poll ratings since joining the coalition with the Tories . Based on the 2010 election result, David Cameron needs to win another 23 more seats to secure a majority in the Commons, while Ed Miliband needs at least  70. Nick Clegg is defending 56 seats, but is braced for heavy losses . The Tories need to win only 23 more seats to obtain a majority in the Commons, while Labour need 70. The polls suggests it could take three or more parties to form a majority, including the SNP, Lib Dems, DUP, Greens and Ukip. Katie Ghose, chief executive of the Electoral Reform Society, said: ‘The fact that we can firmly predict the outcome of over half of the seats being contested this May is a sorry indictment of our outdated voting system. “The average constituency hasn’t changed hands since the 1960s, and some have been under the same party’s control since the reign of Queen Victoria. This is a huge disincentive for people to get out there and vote, and for other parties to challenge incumbents. We have a system which actively discourages voters and parties from taking part. “We urgently need a fairer electoral system to give voice to the many millions of people in safe seats who are not being heard. “Predicting the winners in a majority of seats shouldn’t be possible in a truly dynamic and modern democracy. But sadly that’s exactly what we’ve been able to do. The UK needs a fair voting system to bring our politics into the 21st century and give us a Parliament that actually reflects people’s wishes.” As part of the 2010 coalition agreement, the Lib Dems and Tories held a referendum on changing the voting system to the Alternative Vote, which allows voters to give their first and second choice of candidate. The winner is the first candidate to get over 50 per cent of the vote. However, in the referendum in 2011 it was roundly defeated when 67.9 per cent voted against it.
650 seats up for grabs on May 7 but more than half will not change hands because one party is so far ahead . Electoral Reform Society calls result in 325 seats in England, 5 in Scotland, 20 in Wales and 14 in Northern Ireland . 70% of seats in the East of England are considered safe but only 10% per cent in Scotland as SNP makes big gains .