LONDON--British Prime Minister Rishi Sunak's Conservative Party is set for an electoral defeat on a par with its heavy loss to the Labour Party in 1997, according to a YouGov opinion poll published in the Telegraph newspaper. Ahead of an election expected later this year, the poll predicted Labour was on course to win 385 seats in parliament while the Conservatives will retain just 169, losing more seats than they did in 1997 when Tony Blair led Labour to power. That would represent an 11.5% swing to Keir Starmer's Labour, the biggest collapse in support for a governing party since 1906, the newspaper said. The 14,000 people surveyed by YouGov represented about seven times the usual number of people involved in the firm's polling. The survey was commissioned by a group of Conservative donors, the Telegraph said. Recent polls have repeatedly shown the Conservatives trailing Labour. A YouGov poll in November put Sunak's party behind by 19 percentage points. Asked about the latest forecast of a heavy electoral defeat, Sunak said the only poll that mattered was the national election which must be held by January 2025 but which he has suggested will take place later this year. "There have been lots of polls over the last year. There'll be hundreds more polls. The only one that matters is the one when the general election comes," he told reporters. "And the choice of that election is clear. It's to stick with our plan that is working." Starmer said he was not taking anything for granted in the run-up to the election. "We have to earn every vote, respect every vote, and we should always, always fight like we're 5% behind," he told reporters on Monday.