We tend not to be too poll-obsessed here at LDV – of course we look at them, as do all other politico-geeks, but viewed in isolation no one poll will tell you very much beyond what you want to read into it. Looked at over a reasonable time-span and, if there are enough polls, you can see some trends.

Here, in chronological order, are the results of the nine polls published in July:

Tories 39%, Labour 26%, Lib Dems 19% – YouGov/Fabians (unpublished, 1st July)
Tories 41%, Labour 27%, Lib Dems 20% – ICM/Guardian (14th July)
Tories 42%, Labour 25%, Lib Dems 18% – YouGov/S. Times (18th July)
Tories 38%, Labour 23%, Lib Dems 22% – ComRes/S. Independent (19th July)
Tories 38%, Labour 26%, Lib Dems 20% – Populus/Times (21st July)
Tories 40%, Labour 24%, Lib Dems 18% – Mori (unpublished, 21st July)
Tories 40%, Labour 25%, Lib Dems 20% – YouGov/S. People (26th July)
Tories 42%, Labour 24%, Lib Dems 18% – ComRes/Independent (29th July)
Tories 41%, Labour 27%, Lib Dems 18% – YouGov/Telegraph (31st July)

Which gives us an average rating for the parties in July as follows (compared with June’s averages):

Tories 40% (+2%), Labour 25% (+2%), Lib Dems 19% (+1%)

All three main parties can take a little consolation from this month’s figures, which sees a slight recovery for each at the expense of ‘Others’ (chiefly Ukip, Greens and BNP), who were boosted by their increased exposure during the run-up to June’s local and Euro elections. However, both Labour and the Tories have yet to return to their pre-‘Expenses-gate’ support of 28% and 43% respectively.

So, is a Tory landlside inevitable? It’s very hard to read from these figures. By conventional standards, the Tories’ polling performance is pretty disappointing: despite all Labour’s difficulties, the official opposition party is struggling still to poll above 40%. According to ICM – the only polling company which still uses the same methodology as it did in the 1990s – Labour under Tony Blair was polling between 45-50% in the year leading up to the May 1997 general election. The Tories under David Cameron have ranged between 39-44% during 2009.

However, this isn’t the whole picture. Because, although it’s clear Mr Cameron’s Tories are by no means as popular as Mr Blair’s New Labour was, by the same token John Major’s Tories were by no means as unpopular as Mr Brown’s Labour party is. In the year leading up to the 1997 general election, ICM pegged Tory support in the range 30-37%. Labour under Mr Brown have ranged between 22-32% during 2009. In other words, the Tories can significantly under-perform, by historic standards, and still win a handsome victory if the Labour party under-performs at least as badly. It is, after all, the Labour-to-Tory swing which will determine the extent of Labour’s defeat next time round.

And what of the Lib Dems? Well, 19% might not exactly be in ‘Go back to your constituencies’ territory – but it is the best monthly average rating for the party under Nick Clegg’s leadership. Indeed, you have to go back to April 2007 to find a month when the Lib Dems last did so well. Given the party’s ratings usually sag a little in the summer months – you have to go back four years to find the last time the Lib Dems were doing so well in July – this isn’t bad going.

And what about Nick Clegg’s ratings? Well, again, these too continue to be on the up. Both YouGov and Mori asked their traditional ‘How are the party leaders doing?’ questions – as their wording differs from each other, they always produce slightly different results. But there’s no argument about the trajectory of Nick’s personal popularity:

Nick has now consistently led David Cameron in Mori’s leadership ratings for the last three months. It’s worth remembering that when Nick was first elected leader, in December 2007, just 33% of the public felt they knew enough about him to rate his performance (and they split roughly down the middle between positive/negative). His recognition has doubled over the past 18 months – and, even better, it seems that those who get to know Nick decide they like him. Not a bad spirngboard for his first general election as party leader.