LONDON (Reuters) -Britain’s opposition Labour party has surged to a 33-point lead over the ruling Conservatives, according to a YouGov poll on Thursday, after days of chaos in financial markets triggered by the government’s planned tax cuts. The lead was a record high share for Labour in any YouGov poll as well as the highest figure the party has ever recorded in any published survey since the late 1990s, YouGov said. Earlier on Thursday, British Prime Minister Liz Truss defended her controversial plan to reignite economic growth after huge tax cuts unveiled last week hammered the value of the…