One of the great things about tonight’s ComRes/ITV marginals poll is that it gave us data that we could compare with national polling to see different patterns.

The battleground polling was in the 50 CON seats that are most vulnerable to LAB and as the chart shows the biggest group of change voters since GE10, the LD supporters, have a very different profile of current support compared with the applicable comparative national poll.

Far fewer of the LDs are sticking with their allegiance – an indication of the battle that’s going on and how in these seats supporters of parties not in the top two are likely to get squeezed. As the chart illustrates both CON and LAB benefit.

In the national poll 12% of 2010 LDs have moved to CON against 18% in the marginals. With LAB the figures move up from 26% to 38%. UKIP does better attracting LDs in the national poll than in the battleground while the Greens are the only segment to see an increase with the latter.

All this doesn’t surprise me. Those living in the main battlegrounds experience a very different general election.

Mike Smithson

For 11 years viewing politics from OUTSIDE the Westminster bubble

For latest polling and political betting news follow @MSmithsonPB