Having been marginally behind the Conservatives halfway through the month, Labour managed to end March back in front. But only just:
The gap is too narrow to see on the graph, but Labour’s poll average for March was 33.5%. The Tories were just 0.1 points behind on 33.4%.
Labour’s score is exactly the same as in February. The Tories, by contrast, put on 1.1 points compared with the previous month. Ukip finished March on 14.1%, 0.5 points down on February and a whole point down on January. It’s tempting to conclude the Tories have benefited at Ukip’s expense, but the reality is probably a bit more complicated, with support shuttling around between all the main parties.
Ukip’s average has been drifting slowly but steadily downwards ever since its peak of 16% in October. There seems to be a squeeze afoot, at least as far as the polls are concerned. Whether this bears any relation to how Ukip will perform on 7 May is impossible to tell, of course.
Finally, note that both Labour and the Liberal Democrats appear to have bottomed out and have sunk no further than their respective four-year lows of 33% and 7.5%, both of which occurred in January.
Five weeks from today the last opinion polls before the election will be published. My instinct is that they won’t look very different from how they are now.