In 2017, 10.7% of Labour and Conservative voters switched to the other side

% of main two party voters switching sides

12%

10.7%

9

6

6.5%

3

0

1966

1974

1992

2001

2015

1970

1979

1987

1997

2010

2017

12%

10.7%

9

6

6.5%

3

0

1966

1970

1974

1979

1987

1992

1997

2001

2010

2015

2017

Guardian graphic. Source: British Election Study. Note: No surveys covered the 1979-1983 or 2001-2005 election pairs