MORI have just popped up on their website their latest poll (Tories 41 - up 1, Labour 32 - down 3, Lib Dems 17 - up 4). Although, as Stephen frequently comments, LDV doesn’t generally do polls, this is a good moment to have a look at the picture in the changes in party support in the last few polls.

If you take the last eleven polls and in each case compare support for a party with its support in the previous poll from the same polling company (but treating MORI’s face-to-face and phone polls as two separate series as that’s not really comparing like with like), this is what you find:

• The Liberal Democrats have been up in eight, unchanged in one, down in one (and one unknown)
• The Conservatives have been up in four, down in six and unchanged in two
• Labour have been down in nine and unchanged in two

In other words, the lead the Tories have been opening up over Labour is far more to do with the Liberal Democrats rising in support than to do with the Conservatives’ own popularity.