The data shows that there were only four votes in it

The full detail from today’s MORI London poll is just out and the top-line split is much tighter than the 51%-49% Ken-Boris headline figures that have been reported.

Look at the table above and you will see how close it is. Taking those “certain to vote” – the pollster’s standard filter, of first and qualifying second preferences and you find 207 for Ken against 203 for Boris.

This works out at 49.51% for Boris and 50.48% for Ken. If the former had been rounded up and the latter had been rounded down it would have been 50-50.

This is almost exactly in line with last week’s ICM survey for the Guardian.

Other points to note from the details is that Boris has a good margin amongst white voters but that Ken scores very well with the BMEs where the split is 73% to 27%. The latter figures are based on all responses not just those saying they are certain to vote.

Overall of the 1,000 people interviewed 48% said they would certainly be voting – a proportion which is considerably higher than the 35-36% turnout that we have seen in the previous two mayoral elections.

In the betting Ken’s price has tightened 6/4 while Boris has moved out to 0.6/1.

Mike Smithson