Labour has sunk to its lowest poll rating since the party won its landslide victory last year and continues to trail behind Reform UK with voters.
Just 20% of voters said they would back Sir Keir Starmer’s party at a general election - the party’s lowest approval rating in six years.
This compared to 28% who said they would support Nigel Farage’s Reform, according to the survey by YouGov.
Labour was just 3 percentage points ahead of the Conservatives on 17% of the vote.
Some 16% of those surveyed said they would vote for the Liberal Democrats and 11% the Greens.
EU Relations Minister Nick Thomas-Symonds said the Government has been forced to make some "very difficult decisions to stabilise the public finances early in this parliament".
He told Sky News: "What Nigel Farage does is to stoke problems and offer empty promises for their solution."
It comes as Scottish First Minister John Swinney called for a Reform MSP who defected from the Tories this week to stand down.
Graham Simpson announced the move at a press conference alongside Reform UK leader Nigel Farage on Wednesday. Scotland is set to hold Parliamentary election next May.
Speaking on Thursday, Mr Swinney called on Mr Simpson to quit Holyrood, while also hitting out at the "obnoxiousness" of his new party leader's stance on immigration, which he said was "undermining our legitimate economic aspirations".
Asked if Mr Simpson should stand down, the First Minister said: "Yes, I think he should."
Mr Swinney also hit out at Reform's stance on immigration after a poll this week suggested the issue had moved into the top three most important to Scots.
"I think it's important that we have a reasoned debate about migration in our country," Mr Swinney said.
"Scotland currently today faces a problem, which is that we have a declining working-age population.
"We need to have more people in Scotland working and contributing to our economy.
“I talk to sectors right across the country who are short of staff and need more staff to be recruited to deliver the services they want to deliver, so we need to attract more people to come to Scotland.
"Yet the immigration debate that has been fuelled by the obnoxiousness of Nigel Farage is undermining our legitimate economic aspirations to boost our population and to grow our economy."
With Reform continuing to surge in the polls and Mr Farage targeting the SNP, the First Minister said he remains "very confident" Scots will be more interested in his party's record in Government over the past 18 years.
Mr Simpson's defection came 24 hours before former Labour councillor in Glasgow Audrey Dempsey announced she was joining Reform.
Several high-profile politicians have now defected to Reform.
These include Sir Jake Berry, former Chair of the Tory Party and long-time MP, who joined Mr Farage’s party last month citing them the “true opposition.”
In London, Westminster councillor Laila Cunningham, said she is quitting the Conservatives earlier this year as she is “tired of defending failure”.
She branded a “dereliction of duty” that there are not more police officers in the capital to fight crime.
Former Tory leader of Barnet Council Dan Thomas followed her to Mr Farage’s party in June.
