Parliament is now dissolved. Election day: Thursday 7 May. 650 seats in total, 326 seats needed for a majority. A roundup of recent polling puts Labour and the Conservatives neck and neck, although due to the complications of electoral boundaries, this translates to an overall Labour advantage in key marginals. It's estimated that the Conservatives will need to be regularly polling about 2-3% ahead of Labour to be even in the number of seats. Key facts: The Conservative party has not won an overall majority for 23 years. No governing party has increased its party share of votes since 1974. Vote Labour.