HARDtalk

The battle for power in Britain has long been a bare-knuckle fight between Labour and the Conservatives. But during the current election campaign, the Liberal Democrats have joined the scrap with a vigour which suggests old political certainties could yet be knocked down. Stephen Sackur talks to three doughty political fighters - former ministers, Tony Benn for Labour, Norman Fowler for the Conservatives, and the former leader of the Liberals David Steel. Could this election change the face of British politics?