Clacton by-election aftermath: Parties sent back to the doorstep for 2015 election

If the 2010 general election was dominated by the TV leaders' debates and the relatively new phenomenon of Twitter, it is easy to think that next year's campaign will be the same. But 7 May 2015 is likely to be the Doorstep Election – where the keys to No 10 are won through traditional canvassing.

One of the lessons party strategists are taking from the anti-politics sentiment fuelling the Ukip surge is that voters, cynical about leaders' promises on TV and the culture of Westminster, are more likely to trust friends, family and neighbours when it comes to politics. After their close social circle, the next level of trust is face-to-face interaction with canvassers on the doorstep, followed by their own local MP. It is little surprise, then, that Labour, the Tories and Liberal Democrats are all focusing on the ground campaign for 2015.

Labour has notched up 6.5 million "voter ID contacts" – asking on the doorstep or by phone who someone will vote for. In their 106 target seats, they have made contact with 1.5 million people. In these target constituencies, Labour activists have been making more than 1,500 contacts per month this year – compared to 710 per month in the year before the 2010 election. The party has recruited 100 local organisers to work on key seats.

The Conservatives have invested in VoteSource, a new digital canvass database which replaces their slow, centralised Merlin system. Tory activists can update canvass information remotely using their smartphone or tablet. At the Conservative conference, party chairman Grant Shapps revealed that his "Team 2015" army of volunteer activists has risen from 3,000 last year to 25,000 this year.

The Lib Dems have their own contact system called Connect, similar to the one used for Barack Obama's 2008 and 2012 ground campaigns. But Lib Dem MPs and candidates in target constituencies are also subjected to management-style "key performance indicators" (KPIs), which are used to help determine funding. Targets include delivering set numbers of leaflets, picking up quotas of email addresses, and making doorstep contacts. The Lib Dems have used measures like this for years, but the data has now been formalised and centralised through Connect.

Tim Farron, the Lib Dem president and MP for Westmorland and Lonsdale in the Lake District, tops many of the internal KPI league tables, while international affairs spokesman Martin Horwood is also understood to do well. A mid-table MP said that the new system is "less easy to blag" with inflated numbers. But other MPs are frustrated by the reliance on KPIs. Senior MPs have said that they are being "treated like children"; that certain campaigning advantages, such as name recognition, are "not KPI-able"; and that Connect is a "rough and ready tool".

However a 21st-century election cannot only be fought on the doorstep, and social media and digital strategy remain central to the parties' campaigns. Labour has a "go online to get offline" approach where volunteers and activists are encouraged to not only share infographics on Twitter and Facebook about the bedroom tax and David Cameron's NHS "fails" but also to do something in the real world to encourage people to vote Labour.

Digital strategies must go beyond paying for adverts on Facebook and Google and, as was popular in 2010, getting the leader to do a webchat with Mumsnet. Given that the lack of trust in mainsteam politicians means that friends and family matter more than ever, Labour supporters are being encouraged to promote their party on their social networks. The power of "family and friends" in politics was evident during the Scottish referendum campaign, when the Yes side, in particular, won votes through individuals' passionate argument.

On Twitter, the hashtag #labourdoorstep used by candidates and MPs is ridiculed by journalists and other Twitter users for its ubiquity and on-message platitudes. Yet party sources say that the hashtag is not aimed at cynical journalists but hardworking volunteers. They say it is effective in inspiring others to join in the door knocking – particularly when a candidate says a simple "thank you" on Twitter.

Of course, when all three main party leaders – and especially Ed Miliband – are seeing their personal ratings fall, it makes sense for strategists to place great emphasis on ground campaigns. But, whatever the reason, it is clear that 2015 will be fought on the doorstep.