True blue Westminster and Wandsworth councils in London could be among the casualties as Labour gears up for its most successful night since the 1990s, Tony Blair and Cool Britannia.
The survey suggested Labour will hold 3,500 council seats — a gain of more than 800 — while the Tories will retain about 980, a fall of 548.
Although the elections are for local authorities, the national government under Prime Minister Boris Johnson has endured a series of ethics and standards scandals, including partygate, second jobs and pornography in Parliament.
Mr Johnson, interviewed on British television on Tuesday, argued that he was an honest politician.
If the vote mirrors the opinion poll, it could put more pressure on the prime minister to step down.
Anne-Marie Trevelyan, the International Trade Secretary, was asked about the 550 number and its relevance.
“I am not close to the precise detail but I would expect us to win some and lose some, that would be normal and expected, but what I think we will see is a really strong showing from Conservative voters who want to come out and demonstrate that they know that locally-run councils run by Conservatives are better,” she said.
The opinion poll found that Barnet in London, Southampton on the south coast and Newcastle-under-Lyme in the Midlands could all be lost by the Conservatives, while Labour could gain 16 councils.
The predicted vote share was 24 per cent for the Tories, 39 per cent for Labour and 15 per cent for the Liberal Democrats — figures not seen since Tony Blair was Labour leader.
The pollsters pointed out, however, that previous apparent Labour strength has not necessarily translated into votes.
In the fallout from the partygate controversy, where government ministers held drinks parties at work during Covid-19 lockdowns, Mr Johnson had to pay a fixed penalty notice for breaking the law.
He insisted on Tuesday he was an “honest” politician as he admitted to being “inadvertently” wrong in his comments to Parliament about the partygate row.
“Yes. I think the best way to judge that is to look at what this government says it's going to do and what it does,” he said.
The party has been criticised for its reaction to the Ukraine refugee crisis and the Rwanda plan to send Channel-hopping migrants to East Africa and imposing tax rises while inflation is soaring.
On Saturday, Neil Parish MP resigned his seat after admitting he had watched pornography while in the House of Commons.
Labour leader Sir Keir Starmer said his party has a “real wind in our sails” before the local elections on Thursday.
Asked what success would look like for Labour, he said: “We want to hold seats where we've already got them, and we want to make gains where we can.
“I'm conscious that we've got to earn every vote, I'm taking nothing for granted. What I can tell you is we've got thousands of fantastic activists across the country making the positive case for Labour. There's a real wind in our sails at the moment.”