Security is tight at the Liberal Democrats' spring conference in case protesters get in and harass Nick Clegg. But it wasn't tight enough yesterday to keep out a senior member of the Labour party. The shadow health secretary, John Healey, with his coat collar turned up in secret squirrel style, registered cheekily as the representative of "a non-profit organisation".  The real threat to Clegg is actually from disgruntled Lib Dems, but at least they won't burn the leader in effigy. Not without first offsetting the carbon emissions.  ? as if rugby fans won't have enough of a treat this afternoon as England face Scotland at Twickenham, campaigners for an alternative vote system will be on hand outside the stadium to offer leaflets and advice, just as they did during England v France.  "a surprising number of French fans were stopping to find out more," says one campaigner. "They invariably made a beeline for the lady leafletters."