Polls are tightening as the race to become the 45th President of the United States enters its last week, with Donald Trump attempting to capitalise on Hillary Clinton's latest email scandal.
Until election day on 8 November, follow our poll tracker to keep up-to-date with who's on top. Based on polling data from RealClearPolitics, we have state-by-state predictions and an estimate of the overall electoral college vote.
The news that the FBI has reopened its investigation into Hillary Clinton's use of a private server to send, receive and store government emails has handed Donald Trump an unexpected boost ahead of next Tuesday.
The FBI has obtained a warrant to begin searching newly discovered emails belonging to Huma Abedin, a top aide of Hillary Clinton, with Clinton's use of emails also in the spotlight.
There is no sign that this new investigation will be completed by election day and it seems that Clinton will have to fight the final week of her campaign with unspecified allegations hanging over her.
This is ideal for Trump who was shown to be as many as 14 points behind Clinton in some polls before this latest scandal.
Clinton has been ahead almost continuously in the Telegraph's poll of polls, which takes an average of the last five polls published on RealClearPolitics.
She still retains a lead, but this could change in the coming days with some polls now showing a far closer race.
Source: RCP
The presidential campaign has seen Donald Trump, once a Republican outsider, close the gap on Clinton before falling back after a series of controversies.
Trump has briefly pulled ahead a couple of times - first on 19 May. His polling threatened to consistently overtake Clinton in September, but has since fallen back after a series of allegations of sexual assault were made against him.
Trump is prone to making gaffes and alienating key demographic groups with his comments. His comments on sexually assaulting women, as well as poor performances in the presidential debates, had seen Clinton extend her lead.
However, with the news that the FBI is once again investigating Clinton, a lot could change between now and election day.
The New York Times has worked out that, even one week before previous elections, a simple polling average has differed from the final result by about four percentage points. With the polls being still close, anything could happen.
How does the presidential election work?
Each of the 50 states, as well as the District of Columbia, has a certain amount of electoral college votes to award a candidate, based on the number of members of Congress it has. This is roughly in line with each area's population. Except in Maine and Nebraska, the votes are given on a winner-takes-all basis.
This system matters, as the popular vote is less important than the electoral college vote. Clinton's campaign should be buoyed by big Democratic states such as New York, New Jersey, Illinois and California, and these populous states could lead her to victory with their large number of electoral college votes.
For example, in 2008, Barack Obama won 53 per cent of the vote – but this led to 68 per cent of the electoral college vote. Such highly populated states played a large role when they backed the current president.
The states to watch
Swing states – states that often switch between Democrat and Republican in different elections – are also important.
Why are the US election polls so close?
Both candidates suffer from unpopularity, both within their own parties and among the public at large.
Some big Republicans figures have refused to endorse Trump, while YouGov polling has shown that just over half of Bernie Sanders' supporters would back Clinton.
New York Times and CBS News polling has shown that the two candidates' popularity is limited by the public's lack of trust in both of them.
Just a third of Americas think Clinton is honest and trustworthy, compared to 35 per cent thinking the same of Trump; 57 per cent of people say they don't share Clinton's values, while the number is even higher for Trump, at 62 per cent.
More people think Clinton has the right kind of temperament and personality to be a good president, while Trump has the advantage when people pick the candidate who they think could bring about "real change" in Washington.
US presidential election 2016: the key dataPlay! 02:35
What are the odds on the American presidential election?
It has long been said of predicting sporting outcomes that the bookies don’t get it far wrong, working out probabilities with complicated mathematics based on the choices of their thousands of paying punters.
After last year’s surprise General Election result in the UK, as well as the Brexit vote, many political followers have lost faith in pollsters and prefer to look at the odds to predict the future.
Hillary Clinton has been odds-on favourite since the end of February, but Trump has steadily caught her up as his Republican rivals dropped out. Last July he was a 25/1 shot while Hillary was already at evens.
Coral's latest odds for the next US president are:
Hillary Clinton: 1/3
Donald Trump: 9/4
How could demographics impact the US election?
Age, race, gender and education are all big dividing points in the presidential race, with polling showing that men and whites are backing Trump, and women and ethnic minorities are supporting Clinton.
Race has always been a huge dividing line in the US election, and the clash between Trump and Clinton is no different. Just 17 per cent of Hispanics and three per cent of black people back Trump, according to recent polling.
This could prove significant in this election. For example, Hispanics account for more than a fifth of the population in four key swing states.
Education is another big demographic division in the race - and there's a reason why Trump said he "loved the poorly educated".
Among high school graduates or those with a lower level of education, Trump has the backing of 44 per cent - compared to the 36 per cent who support Clinton.
This could prove significant in the swing states of Georgia and Nevada, which both have a high proportion of people failing to graduate from high school.
What effect have the presidential debates had on the polls?
Hillary Clinton secured a boost from the first US presidential debate on Sept 26 to lead Donald Trump nationally.
Mrs Clinton gained four percentage points in the wake of the showdown in New York which was watched by a record 84 million people on television.
However, only nine per cent of viewers changed their minds about who they were supporting because of the debate, with many waiting until after the final two debates to decide.
Clinton's polling also increased around the second presidential debate on Oct 9, which took place just after a series of lewd comments made by Trump about women were released to the public.
How have the Trump comments affected the polls?
Trump's ratings have sunk as old clips have been released showing Trump bragging about sexually assaulting women.
His polling had threatened to overtake Clinton in September, but a series of lewd comments that have been released have dented his popularity - particularly among women.
As voting opened as these comment were well in the public eye, a gap of five percentage points between him and Clinton had opened. Many news publications and betting companies had increased their odds on Clinton gaining the presidency.
It is too early to say whether Trump can pull it back, capitalising on the news that the FBI is once again investigating Clinton.