Who will win the general election and by how much? Check what the latest opinion polls say and follow updates from the BBC’s senior elections and political analyst Peter Barnes. The poll tracker will be updated as the campaign unfolds.
Latest updates from senior elections and political analyst Peter Barnes
15 May: Labour improvement
Four polls over the weekend reinforced the picture of a Labour improvement during the course of the campaign so far. ORB, Opinium, ComRes and YouGov all had them at 30% or above – clearly above the levels seen at around the time the election was announced.
However, this increase has not come at the expense of the Conservatives who remain in the mid-to-high 40s with a commanding lead.
The main losers have been UKIP, who are down in the 3-6% range.
If the current polls were reflected in the final result it would mean the two main parties between them capturing a significantly larger share of the vote than at recent elections.
In 2015, they received a total of 69%. The polls suggest a joint share of almost 80%.
You have to go back to 1992 to find an election where the total Conservative and Labour share was close to that – the figure was 78%. The last time it was above 80% was 1979.
Scotland, Wales and Northern Ireland
All the polls shown in the tracker report vote intention share across Great Britain, but that’s not very helpful for working out what’s going on in parts of the UK where other parties stand.
However as we’ve only seen two campaign polls in Scotland, two in Wales and one in Northern Ireland so far, there’s not very much evidence to go on.
Having said that, both of the Scottish polls, conducted by Survation and YouGov, have given the SNP over 40% with a clear lead over the Conservatives on 28% and Labour down in third place on 18%.
In Wales, two YouGov polls have put the Conservatives ahead of Labour, but with a smaller gap than across Britain as a whole.
Like in the national polls, Labour’s share has seen an improvement from the beginning of the campaign. Plaid Cymru are back in third place
In Northern Ireland, the single Lucid Talk poll gave the DUP a narrow lead over Sinn Fein with the UUP, SDLP and the Alliance all some way back.
Most important issue
As well as asking people which party they intend to vote for, pollsters also ask which issues are the most important. In 2015 the three biggest issues were the NHS, immigration and the economy.
A significant change at this election is the emergence of Brexit. Polls conducted since the election was called have put it at the top of the list of important issues ahead of the NHS in second place with the economy and immigration battling it out for third.
This may help to explain, at least in part, the Conservatives’ lead in the polls.
So far as we can tell, they’ve managed to attract the support of a large number of new voters who backed leave at last year’s referendum whilst holding on to most of their own supporters who backed remain – many of whom now think that the Government has a duty to implement the outcome of the referendum.
11 May 2017: Should we ignore the polls?
As everybody knows, the polls got the 2015 general election wrong.
They suggested that the likely outcome was a hung parliament but, as we know, the Conservatives won an overall majority. So is it worth paying attention to them this time?
Well, we certainly shouldn’t assume that the result will be exactly what the polls say. But that doesn’t mean they’re completely useless.
For one thing, critics have perhaps exaggerated other polling “disasters”.
The belief that the polls were just as bad at the EU referendum and in the US Presidential election is widely held. However, whilst some polls gave a misleading picture at the referendum, others were pretty close.
We reported at the time that the polls overall indicated a very narrow race in the weeks running up to referendum day.
Similarly, at the US election, the national polls weren’t that far off in terms of the share of the vote won by Donald Trump and Hilary Clinton – Clinton actually won the popular vote by over 2%.
It was state polls that were unreliable and led to a misleading impression as to who would emerge from the Electoral College system as president.
In both cases, if all we’d taken from the polls was that the votes would be close, we would have been on the right lines.
The polling companies have also made adjustments to try to prevent the problems of 2015 from happening again and to resolve issues that arose at the referendum.
These methodological changes vary from pollster to pollster but there are some general trends.
Several of them now ask the people who take part about their educational background. The aim, as with questions about class, age, gender and region is to get a sample of people who are representative of the population as a whole.
Others have developed more sophisticated ways to estimate how likely it is that somebody who takes part in a poll will actually vote. Just asking people whether they will vote is not a good guide.
Of course, we can’t be sure whether these adjustments will make the polls more accurate. So some people will no doubt decide to ignore them all together.
But there’s still clearly an appetite for them.
No fewer than 30 have been conducted since the Prime Minister made her surprise announcement on 18 April.
That’s more than one a day.
What’s happened since the election was announced?
It’s now three weeks since the election was announced and the official campaign is well under way.
After Theresa May’s surprise statement, the Conservatives saw their poll rating jump with several polls suggesting a comfortable 20 point lead.
Since then, nothing very dramatic has happened. There has been a modest uptick for Labour, who are generally up to the high 20s or around 30 – up from the mid 20s just after the announcement.
But that still leaves a very large gap between the main two parties.
UKIP seem to have slipped a little further down and perhaps the Lib Dems have also fallen back a bit, although these trends are not clear.
How are polls actually carried out?
Most opinion polls, and all of the ones covered in the BBC poll tracker, are either conducted by telephone or online.
For phone polls the polling company rings up landline and mobile numbers.
In principle, anyone with a phone could be asked to participate.
For internet polls, the company maintains a panel of people who are prepared to take part. For each poll they will contact the required number of panel members.
In both cases the company will aim to survey a sample of people who are representative of the country as a whole – in terms of age, gender, social class, etc.
They will generally then apply weighting adjustments if one or other group is over-represented or under-represented in their sample.
It’s also common to seek a representative sample or apply a weighting based on past-voting behaviour.
Polls included: All polls conducted by companies which are members of the British Polling Council. This includes: BMG, ComRes, GfK, ICM, Ipsos-Mori, Opinium, ORB, Populus, Panelbase, Survation, Kantar Public (TNS-BMRB) and YouGov.
Sample area: Polls record voting intention for Great Britain (England, Scotland and Wales)
Dates: Polls are ordered by latest date of fieldwork.
Margin of error: Polling companies generally claim that 95% of the time, a poll of 1,000 people will be accurate within a margin of error of +/-3%. This means that a figure in the poll could be up to three percentage points higher or lower than that shown.