If the polls were translated into reality in the election on May 2, it would see Mr Khan win the biggest margin of victory since the mayoralty’s creation in 2000.
The most recent poll, conducted in November 2023 by Find Out Now for the Evening Standard, put Mr Khan on 46 per cent, with Ms Hall on 25 per cent. Liberal Democrat candidate Rob Blackie and Green candidate Zoë Garbett each had nine per cent, with Reform UK's Howard Cox on six per cent.
But the mayor told the Standard on Tuesday: “The most important poll is on election day. I’ve been in this business far too long to believe the polls.
“In 2016 we believed the polls and the [Brexit] referendum was lost. In 2016 many of my friends in America believed the polls - and then Donald Trump was elected.
“I’m quite clear, this is an election like no other, because the Government’s changed the rules in relation to London mayoral elections, [with] photo ID [now required], [the introduction of the] first past the post [voting system], but also a lack of awareness about these elections taking place.”
Asked whether Ms Hall also believes that the polls are wrong, a spokesman for the Conservative candidate said that she and her campaign do not comment on polls.
Similar poll leads for Mr Khan of 20 or more points were reported in the months leading up to the last mayoral contest in 2021, though the lead narrowed to 12 points in the final couple of polls before the election.
In the election itself, Mr Khan’s lead over Tory candidate Shaun Bailey ended up being just 4.7 points among first preference votes, rising to 10.4 points once second preferences had been counted.
Until this year's election, mayoral contests were conducted using the supplementary vote system - which allowed voters to put down a first and second preference for mayor. The top two candidates in terms of first preference votes then had their second preference votes added to their totals to calculate the winner.
Following national changes introduced by the Government, mayoral elections will now use the first past the post system, meaning that the winning candidate only has to receive more votes than any other.
The largest ever margin of victory was achieved by Ken Livingstone in the 2000 election, when he ran as an independent. He came 11.9 percentage points ahead of Conservative candidate Steven Norris in the first round, rising to 15.8 points after second preferences had been accounted for.
“I’m under no illusion - I could lose the election,” said Mr Khan.
On top of the mayor’s concerns about the voting system changes having a disproportionate impact on his election chances, he also believes that the requirement for voters to have photo ID will disproportionately prevent his voters from casting their ballots.
He has previously warned that “900,000 Londoners could be silenced” - a figure derived from Labour-commissioned Opinium polling which found that 15 per cent of Londoners do not have voter ID.
The Government has dismissed such concerns, pointing out that “the vast majority of voters in the polling station – 99.75 per cent – cast their vote successfully at the local elections in England in May ”, though the Electoral Commission believes that statistic underestimates the total number of people who were unsuccessful in voting.
Mr Khan added: “Many Londoners don’t realise there’s an election on May 2. So I’m doing what I can to remind Londoners of all the things we’ve achieved over the last eight years, despite a Conservative Government.
“Free school meals for the first time ever. Freezing TfL fares for five of the last eight years, freezing them next year as well. Record numbers of council homes and completions. Mentors for young people, constructive things for young people.”
Ms Hall has argued that the election “is our chance to get a grip on crime. And scrap the Ulez expansion, so that hard working Londoners don’t have to pay £12.50 a day to drive”.
She has also promised to end what she calls the mayor’s “war on motorists”, stop his “inappropriate tower blocks” and “build family homes” instead, and “make London a cleaner and greener city”.