LONDON, Sept 29 (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 pound and government bond prices.
The YouGov poll of voting intention conducted over Wednesday and Thursday showed 54% support for Labour and 21% for the Conservatives. It was a survey of more than 1,712 British adults.
Another YouGov poll earlier this week had shown 45% of voters backing Labour compared to 28% support for the Conservatives.
Three other polls on Thursday also showed large leads for Labour - Survation put Labour's lead over the Conservatives at 21 points; Deltapoll showed Labour 19 points ahead; and Redfield & Wilton Strategies had Labour 17 points ahead.
Truss took office on Sept. 6 after winning the Conservative Party's leadership contest following Boris Johnson's resignation as prime minister. The next national election is likely to be held in 2024.
Opposition leader Keir Starmer said during his party's annual conference this week that it was Labour's best chance to win power since 2010, following four straight election defeats.
