So from Feb 13 when Labour were at their highest poing 41.9% on average with pollsters that month to 29.3% the month after the General Election.
Where as the Conservatives went from 30.9% average in Feb to 38.3% in June 2015 not quite their high point which they reached in August.
Great google doc made by @britainelects
link to doc
Month | Year | CON | LAB | LDEM | UKIP | GRN | OTH |
February | '16 | TBC | TBC | TBC | TBC | TBC | TBC |
January | '16 | 38.9 | 31.1 | 6.4 | 13.7 | 3.3 | 6.6 |
December | '15 | 38.9 | 30.9 | 6.7 | 13.6 | 4.0 | 6.0 |
November | '15 | 38.8 | 30.3 | 6.9 | 13.5 | 3.3 | 7.4 |
October | '15 | 38.0 | 31.8 | 7.2 | 12.7 | 3.5 | 6.8 |
September | '15 | 38.4 | 31.4 | 7.4 | 13.1 | 3.3 | 6.2 |
August | '15 | 40.0 | 30.3 | 7.3 | 11.8 | 4.3 | 6.5 |
July | '15 | 38.3 | 31.0 | 7.7 | 10.7 | 5.7 | 6.7 |
June | '15 | 38.3 | 29.3 | 8.7 | 10.7 | 5.7 | 7.3 |
May | '15 | 34.6 | 32.9 | 8.9 | 12.7 | 4.7 | 6.2 |
April | '15 | 33.6 | 33.7 | 8.3 | 13.7 | 5.0 | 5.9 |
March | '15 | 33.5 | 33.6 | 7.7 | 14.1 | 5.6 | 5.5 |
February | '15 | 32.5 | 33.5 | 7.6 | 14.4 | 6.4 | 5.6 |
January | '15 | 31.8 | 33.2 | 7.4 | 15.2 | 6.8 | 5.6 |
December | '14 | 31.7 | 33.5 | 7.6 | 15.6 | 5.9 | 5.6 |
November | '14 | 31.7 | 33.1 | 7.7 | 15.9 | 5.6 | 6.0 |
October | '14 | 31.8 | 33.5 | 7.8 | 16.5 | 4.8 | 5.7 |
September | '14 | 31.7 | 35.6 | 7.8 | 15.0 | 4.7 | 5.2 |
August | '14 | 32.9 | 36.3 | 8.3 | 13.4 | 4.3 | 4.8 |
July | '14 | 32.7 | 36.5 | 8.4 | 13.1 | 4.7 | 4.6 |
June | '14 | 32.1 | 35.8 | 7.9 | 14.7 | 4.8 | 4.6 |
May | '14 | 32.1 | 34.9 | 8.7 | 15.0 | 4.1 | 5.2 |
April | '14 | 32.4 | 36.5 | 9.4 | 14.1 | 2.6 | 4.9 |
March | '14 | 33.4 | 37.4 | 9.7 | 12.0 | 2.6 | 5.0 |
February | '14 | 32.7 | 38.2 | 9.5 | 12.6 | 2.5 | 4.5 |
January | '14 | 32.2 | 38.0 | 9.8 | 12.6 | 2.6 | 4.8 |
December | '13 | 32.9 | 38.7 | 10.1 | 11.1 | 2.7 | 4.6 |
November | '13 | 31.9 | 38.8 | 9.8 | 11.8 | 2.8 | 4.9 |
October | '13 | 32.7 | 38.3 | 10.0 | 11.6 | 2.7 | 4.7 |
September | '13 | 32.7 | 38.2 | 10.1 | 11.5 | 2.7 | 4.8 |
August | '13 | 31.9 | 38.0 | 10.4 | 12.2 | 2.7 | 4.7 |
July | '13 | 31.6 | 38.5 | 10.3 | 12.4 | 2.7 | 4.6 |
June | '13 | 30.0 | 38.1 | 9.8 | 14.1 | 3.0 | 5.0 |
May | '13 | 28.7 | 37.9 | 9.6 | 16.2 | 2.7 | 5.0 |
April | '13 | 30.6 | 39.6 | 10.4 | 12.5 | 2.5 | 4.3 |
March | '13 | 29.5 | 40.0 | 11.3 | 12.5 | 2.2 | 4.6 |
February | '13 | 30.9 | 41.9 | 10.4 | 9.8 | 2.2 | 4.8 |
January | '13 | 31.7 | 41.5 | 10.3 | 9.8 | 2.3 | 4.4 |
The average of Westminster voting intention polls conducted during each month. |