A female protester hurled green custard into the face of Lord Mandelson today before calmly walking away and evading arrest in an embarrassing security breach. The Business Secretary had just emerged from his chauffeur-driven Jaguar outside a low-carbon summit in Central London when the woman approached carrying a plastic cup. After exchanging a few words with Lord Mandelson she emptied its contents – cornflower paste and green food dye - directly over the minister. The peer hunched over in appa