The worst thing you can do in analysing polls of voting intention is to get excited at polls that show something exciting and different and ignore those that show the same old pattern. Occassionally the unusual poll will herald a genuine movement in public opinion – after all, whenever there is a change, one poll has to pick it up first. More often than not, the unusual poll will turn out to be a freak result, the product of unusual sampling or methods. If there is genuinely a change in public opinion, other polls will pick it up sooner or later, so it’s always wise to withhold your judgement.

Today we have one of those unusual polls, and we have the overexcitement you’d expect. ICM’s monthly poll in the Guardian has topline figures of CON 39%(+3), LAB 33%(-2), LDEM 8%(nc), UKIP 7%(-2), GRN 7%(+3) (tabs). This is pretty odd all round – a storming six point lead for the Tories, up on thirty-nine percent; the Greens and UKIP equal on seven percent.

In the Guardian’s write up they are rightly dubious, and include a welcome caveat from ICM’s Martin Boon about the inevitability of random variation and the sample perhaps being a touch too Tory. I’ll just leave it with the usual caveats – it’s one poll, and an odd looking one at that. Sure, it could be the start of some Tory surge, but if it is we will see it echoed in other polls today…and luckily enough we have at least three of them.

Populus this morning had topline figures of CON 33%, LAB 33%, LDEM 8%, UKIP 15%, GRN 5% (tabs). The Conservatives are up two points (possibly helped by an update in weighting targets), but no big tory lead.

Still to come are the weekly Ashcroft poll and the daily YouGov poll. Come the end of the day, the way to judge where we are is too look at all them as a whole – not fixate on the unusual one.

UPDATE: Lord Ashcroft’s weekly poll has topline figures of CON 33%(-3), LAB 33%(-1), LDEM 9%(+3), UKIP 13%(+3), GRN 6%(-1). Changes are from a fortnight ago – Ashcroft took a week off to avoid bank holiday fieldwork. As with today’s Populus poll, there is nothing here to support the big Tory lead in the ICM poll. Full details are on Lord Ashcroft’s website here.

UPDATE2: Finally the daily YouGov poll for the Sun has topline figures of CON 33%, LAB 34%, LD 8%, UKIP 13%, GRN 6% – a one point Labour lead. Putting all four polls together that ICM poll looks very much like an outlier. Such things are an unavoidable part of polling – and well done to Guardian for reporting it in a heavily caveated way within the context of other polls showing no movement, rather than getting all excited about it.

As usual for a Monday we have three GB polls today – Populus, Ashcroft and YouGov. In a election campaign that has so far seen polls that are virtually static these were awaited in the hope they’d shed some light on the impact of the Paxman interviews last week. In the two post-Paxman polls at the weekend YouGov had shown a larger Labour lead than usual, but ComRes had shown a larger Conservative lead than usual. The question was whether today’s polls would shed any light on whether there was any movement, or just normal sampling error.

Populus’s twice-weekly poll has topline figures of CON 34%, LAB 34%, LDEM 8%, UKIP 15%, GRN 4% (tabs). Populus have typically been showing a small Labour lead in their polls over the last few weeks, so this is more Tory than their average poll, but well within the normal margin of error.

Lord Ashcroft’s weekly poll has topline figures of CON 36%, LAB 34%, LDEM 6%, UKIP 10%, GRN 7% (tabs). This is a small shift towards the Conservatives since Ashcroft’s poll last week, but a two point lead is very much in line with the average of his recent polls, so is nothing to suggest any real movement.

YouGov’s daily poll for the Sun has topline figures of CON 35%, LAB 35%, LDEM 8%, UKIP 12%, GRN 5% – back to more typical figures of neck-and-neck.

Looking at the five polls conducted since the Paxman debate, things are starting to look much more like “no change” that a Labour or Conservative boost – there is a bit of movement in either direction, but no clear consistent trend. The seven way debate this week may have more impact, if it’s not just a complete mess.

Note however, that a lack of change in voting intention figures doesn’t necessarily means the interviews last week had no impact at all. YouGov’s weekend poll also saw a significant improvement in Ed Miliband’s ratings and this was echoed in Lord Ashcroft’s poll today. While David Cameron still led on most measures, his lead over Miliband had dropped across the board since Ashcroft last asked in February: Cameron’s lead on representing Britain abroad was down 8 points to 28, on making the right decisions when they are unpopular down 6 points to 23, on having a clear idea of what he wants to acheive down 8 to 19, on leading a team down 6 to 30, on doing the job of Prime Minister down 5 to 26. Miliband’s lead on understanding ordinary people rose 8 points to 12. Of course it would be wrong to necessarily put this down to the interviews, there were signs of improvements in Miliband’s ratings in polls before last week, but it does look as if he’s narrowing Cameron’s advantage.

Meanwhile there were also Wales and London polls out today. The latest Welsh YouGov poll for ITV and Cardiff University has topline figures of CON 25%(nc), LAB 40%(+1), LDEM 5%(nc), Plaid 11%(+1) UKIP 14%(nc), GRN 5%(-1) – Roger Scully’s analysis here. A new ComRes London poll for ITV London has topline figures of CON 32%, LAB 46%, LDEM 8%, UKIP 9%, GRN 4% (tabs).

Note that despite what you may be seeing on Twitter, there is NOT a new ComRes Scottish poll – it’s just people getting excited over a small sub-sample of 70 spitting out the sort of strange and outlandish results that are inevitable with small sub-samples of 70 people.

The rest of the the YouGov budget polling is now up on their website here. It suggests a broadly positive reaction to the budget and a significant jump in Osborne’s own ratings. Overall 42% think the budget was fair, 27% unfair. Most people think it will make little difference to the country or to their own finances, but of those who do there more think it will have a positive impact than a negative one. 40% of people think Osborne is doing a good job as Chancellor (up 6 from before the budget) and his lead over Ed Balls on who would make the best Chancellor is up to 20 points.

Just because something is approved of though, it doesn’t necessarily mean it has any effect on voting intention. The second of this week’s Populus polls, also conducted entirely after the budget, has topline figures of CON 31%, LAB 34%, LDEM 9%, UKIP 17%, GRN 5%. No sign of a budget bounce there – but I’ll repeat the same caveats I made after the YouGov poll last night. We could just be seeing random variation, and news events don’t have an instant effect anyway – these two polls were after the budget, but many responses would have been before the media reaction (just because something has already happened, doesn’t mean the respondent already knows about it). Wait and see if the broader average moves in the week ahead.