The British Election Study is pleased to announce the release of wave 15 of the British Election Study Internet Panel. Wave 15 was conducted in March 2019, immediately before the original Brexit deadline. In total 30,842 respondents took wave 15 of the British Election Study. 20,129 of these also took wave 14, an overall wave on wave retention rate of 64.8%. 3,206 respondents took all of the first 15 waves of the survey, 10.6% of respondents who originally took wave 1. Some respondents return after dropping out, so 32.9% of all wave 1 respondents took wave 15.