While most polls point to a straight fight between current Mayor of London Boris Johnson and former Mayor Ken Livingstone, floating Facebook and torn Twitter voters could tip the balance of power in the race for City Hall.
In the four years since the last 2008 Mayoral campaign, social networking use has exploded across Britain and digital campaigning has been at the heart of much of the fight between the Conservative and Labour candidates this time around.
From Twitter feeds to YouTube videos, interactive maps and Facebook groups, both Boris and Ken have used cyberspace to target younger voters and raise awareness of specific local issues.
The other five London Mayor candidates too have taken to the online world to spread their messages.
But it’s not just the City Hall race that is benefiting from a digital push. Politics in general has recently experienced a resurgence in engagement thanks to tweets and status updates and it's hope this will give local elections - also taking place today - an extra boost.
The Electoral Commission believes technology is now playing a key part in shaping British democracy, reducing apathy among voters and ensuring people sign up to mark their "X".
During the run-up to the local elections, the Electoral Commission has worked with Facebook's Democracy UK page to push people to its aboutmyvote.co.uk website and encouraged users to pass the message on through their wall posts and statuses.
A spokesman said: "Social media, due to its popularity, has become an increasingly important part of the Electoral Commission's campaigns to encourage people to register to vote.
"This resulted in approximately 6,268 forms being downloaded via Facebook.
"Twitter has also formed a central part of our campaigns and we have used this, and Facebook, to spread our viral video, Ballot Box man.
Sarah Garret, Communications Manager at London Elects, the body behind the Mayoral and Greater London Assembly elections, agrees digital is key.
She explained: "Our campaign is all about providing Londoners with the information they need so they know how to vote and how the Mayor and Assembly affect them.
"As digital technology has moved on a great deal since the last election four years ago, our website has been redesigned to reflect that. It is integrated with social media tools, including Twitter, Flickr, YouTube and Facebook, to reach a wider community – particularly younger voters.
"We're advertising on social media sites as well as directly engaging with users, and we've had thousands of referrals to our website from Facebook and Twitter in the last week alone."
Martin Hoscik, editor of blog MayorWatch.co.uk, also believes digital and social media tools have changed the way the London candidates have conducted their campaigns compared to four years ago.
He said: "The main four candidates and their campaigns have been especially good at using Twitter both to engage with voters and supporters and to re-enforce policies and lines of attacks during both live and pre-recorded broadcast debates.
"It has allowed them to expand on points made during debates and to expand on statements and arguments by linking to manifestos, articles and external sources within the online discussions that have taken place.
"This is a level of interaction that goes beyond anything the candidates did in 2008."
But it’s not been without its problems. As well as giving a louder voice to each candidate, social media has also allowed his or her opponents to have a greater say.
Lord Alan Sugar’s revelation on Twitter that people should not vote for Ken Livingstone spread like wildfire across the internet reaching the wider offline media.
And as the campaign began, Boris Johnson found himself on the receiving end of criticism and controversy for initially attempting to use the official Mayor of London Twitter account before opening a new specific one, @BackBoris2012.
Digital expert Drew Benvie, UK group MD at PR firm Hotwire, believes social media has ensured politics is now more transparent and open.
He said: "It's plain to see that social media is popularising politics. From the trending topics on Twitter to the communities amassing on Facebook, what has changed is the ability for the politicians to reach their audience with a call to action faster and more directly than ever, whether that’s to vote, pledge or pass on.
"While we are seeing membership of political parties and engagement in local party politics falling, social media has enabled us to get more engaged in local issues, with people who would otherwise not have now doing so.
"Social media is part and parcel of the public consciousness in ways that are bringing more challenges to politics but more openness and transparency too, which is certainly good news for most of us."
But Shana Pearlman, an author and a digital expert on US politics, feels the UK still has some way to go if it is to match the social media fever that engulfs elections Stateside, which often includes dirty tricks.
She explained: "Tweets about the London Mayoral election demonstrate that UK political advocacy groups are starting to grasp the power of Twitter.
"Hashtags like #notkenagain and #yesweken show that both sides are filtering their message through partisan supporters, who are broadcasting and amplify each candidate’s message.
"But in this election, the buzz is very much dependent on traditional media stories which are shared on Twitter by supporters of one candidate or another."
She added: "The next frontier is the role social media is beginning to play in American elections, where partisans use Twitter to broadcast stories that might not break into the traditional press, like the #Obamaeatsdogs meme.
"No longer do a few editors in Washington or New York determine what makes news; if enough people get it to trend on Twitter, it becomes news, and the President itself jokes about it at the White House Correspondents’ Dinner."