Sir Keir’s approval rating has also fallen to a record low of -41%, with two-thirds of Britons holding a negative view of the Prime Minister.
Worryingly for the PM, more than a third of Labour voters (36%) have an unfavourable view of their party leader in the poll carried out in December.
Since coming into office, the Government has been hit by a number of scandals – with Sir Keir and other frontbenchers accused of hypocrisy for accepting thousands of pounds of freebies.
Sir Keir himself took thousands of pounds in work clothing and pairs of glasses from millionaire donor Lord Waheed Alli. He later said he would not be accepting any further gifts.
Chancellor Rachel Reeves has been heavily criticised for a series of unpopular economic policies, including the decision to remove the winter fuel payment from the vast majority of pensioners.
Farmers have protested against plans to force many more to pay inheritance tax, while the continued arrivals of migrants in small boats across the Channel have put pressure on immigration.
Labour has also lost 33 council seats it has contested across England, Scotland and Wales since the General Election.
As Reform UK’s membership grows to record-high figures, party leader Nigel Farage is more popular than Sir Keir – although the Clacton MP still has a -34% approval rating.
Tory leader Kemi Badenoch’s favourability rating has plunged to -31%, down from -20% in November.
However, a third of voters say they have not yet made up their mind about the North West Essex MP.
