The BBC's Norman Smith grapples with a Lego representation of the podium and its participants ahead of a TV election debate which will feature seven political parties.

The TV clash will feature the Conservatives, Labour, the Lib Dems, UKIP, the SNP, Greens and Plaid Cymru leaders for the first time.

The debate will be shown on ITV from 20:00 to 22:00 BST