One of the most closely-contested British general election campaigns for decades formally gets under way today.

After a final official reception with the Queen, David Cameron will return to Downing Street this afternoon to accuse Labour of planning huge tax rises.

Meanwhile, Ed Miliband will make a pitch to business leaders, claiming the Tories' EU referendum will harm growth.

Projections suggest the SNP could be the third biggest party at Westminster after the 7th of May.

Leader Nicola Sturgeon reckons the big parties are rattled.