Having governed in coalition with the Liberal Democrats since 2010, the Conservatives won 330 seats and 36.9 % of the vote, this time winning a working majority of twelve seats. (en.wikipedia.org)
Though they are not the most marginal seats in the country, David Cameron must win over their voters if the Tories are to win a working majority in the House of Commons. (channel4.com)
[1] This could be interpreted as including the option of an election in 1975; [3] however, Labour won a working majority, and had no need of another general election. (en.wikipedia.org)