But Starmer’s red lines failed to win over many Leave voters at all: 85 percent of those who would eventually back the party in 2024 wanted to rejoin the EU outright, according to the British Social Attitudes Survey, a regular comprehensive academic survey of public opinion. Labour’s coalition was if anything more pro-EU than when Starmer took over from Corbyn.
The Labour leader was also wrong about needing to win over Brexit supporters to reach Downing Street in the first place. The Tories, who had governed for 14 years straight, had imploded — and Labour was returned with a vast parliamentary majority of 160 seats.
“Labour’s stance on Brexit reflects a belief that, to win the 2024 election, the party would need to reconnect in particular with those of its former supporters who voted Leave in 2016 and went on to back Boris Johnson in 2019,” the authors of the study, including veteran psephologist John Curtice wrote. “In practice, however, Labour’s support came overwhelmingly from those who say they would vote to rejoin the EU.”
Curtice, who spent the evening of the 2016 referendum crunching the numbers for the BBC, told POLITICO he had realized the pro-Brexit campaign was on course to win after Sunderland, a Labour heartland, declared for Leave. In 2024, Starmer’s Labour won every parliamentary seat in the city.
Going for growth
Given the scale of Labour’s 2024 victory, it’s unlikely that this technicality bothered the new prime minister at the time. But it would have enduring practical consequences for his government.
Despite serving no discernible political purpose, the red lines on single market and customs union membership have effectively bound Starmer to the basic framework of Boris Johnson’s Brexit settlement — one which economists now estimate has cost the U.K. six to eight percent of GDP per head by 2025.