Labour now enjoys a 33-point lead over the Conservatives, after days of market turmoil sparked by Kwasi Kwarteng’s mini-budget on Friday.
Liz Truss’s Government has been engulfed in a political and economic crisis since then, after the £45 billion tax-cutting package spooked markets and forced the Bank of England to intervene.
Now, days before Truss arrives at her first Conservative Party conference as Prime Minister, a poll from YouGov suggests that Labour currently sits on 54% – 33 points ahead of the Tories on 21%.
According to the poll, support for the Conservatives has fallen by seven points in the past four days, handing Labour a mammoth lead against the party.
The poll, which surveyed 1,712 adults on Wednesday and Thursday, comes as Truss and Kwarteng have struggled to reassure economists and the public alike about the merits of their economic strategy.
The lead is, according to YouGov, the highest of any recorded poll since the late 1990s.
Voters appeared also more willing to pick Sir Keir Starmer when asked who would make the best Prime Minister, with 44% choosing the Labour leader compared with 15% for Ms Truss when asked to choose between the pair.
While Truss has said before that she is prepared to be an unpopular prime minister if it means delivering growth for the UK, the figures will nonetheless likely prompt serious questions about her leadership only weeks into the job.
What will particularly worry the Conservatives is that only 37% of 2019 voters said they would stick with the party at the next election.
Elsewhere, the poll puts the Liberal Democrats on 7%.