Opinion polls since the last general election have shown fluctuating fortune for the major three parties, and the emergence of wildcard option UKIP. Although many elections are described as ‘too close to call’, this one is genuinely difficult to predict, except to say that it will be very difficult for any party to reach a workable majority. The parties are therefore having to approach their manifestos with another round of coalition talks in mind.
Source: ComRes voting intention polls for The Independent, Independent on Sunday, Sunday Mirror
Measurement and evaluation