In 42 days the British public go to the polls in what is turning out to be the least predictable election ever. Uniform swings are out of the window, closely followed by the accepted two-party system.

Here is our guide to the seats that we think are the ones to watch as the election develops:

UKIP: Everyone is talking about how many seats the ‘People’s Army’ can take off the existing parties and the lack of the uniform swing can make the number particularly hard to work out. But UKIP will be bitterly disappointed if they don’t at least retain their existing two MPs: Mark Reckless (Rochester and Strood) and Douglas Carswell (Clacton).

They are also expecting to take Thanet South, where Nigel Farage is standing and Thurrock. But these are in what are now the UKIP heartlands of Essex and Kent where they are fighting the Tories. It’ll be much more interesting to see what happens in Labour heartlands like Great Grimsby, Rotherham and Heywood & Middleton. They are a close second in all three.

Conservatives: Secretly the Tories are expecting to keep the keys to Number 10 in 42 days, albeit through some sort of coalition. They need to cling to the seats they already hold and have developed the 40/40 strategy in which they sure up their 40 most marginal seats whilst pouring resources into 40 target seats.

They will need to hold northern marginal seats like Morecambe and Lunesdale, which has a majority of just 866 over Labour and Stockton South were it is just 332. UKIP will take seats in the South but the risk from Labour in the north is far bigger.

Labour: Are heavily targeting all of the northern marginal mentioned above, and will probably take some of them. Add to this the risk the Tories face from UKIP and things should be looking rosy for Ed Miliband, but they really are not.

Since the Scottish referendum the SNP has surged in the polls in Scotland, with some polls predicting that they might take 30 seats off Labour. This is highly unlikely but the SNP would be happy with 25 of the 59 seats in the country, even this number would be a disaster for Labour.

So if it looks like Kilmarnock and Loudoun, where Labour has a thumping 12k majority over the SNP, is going to go to the Nationalists then the political map will have changed in Scotland.

Liberal Democrats: It is hard to overestimate the pessimism in Lib Dem circles about the election. They do have their targets but in truth they are just desperate to cling to anything. They should be safe in seats were they have well established MPs such as Nick Clegg’s seat of Sheffield Hallam. But where MPs are standing down such as Berwick-upon-Tweed they are likely to be beaten.

Overall the situation on the ground is very unpredictable and some pollsters have begun looking at individual seats. The real confusion here is that many seats now have four serious parties competing for them. This makes predictions hard if not impossible.

So perhaps the simplest prediction to make is this: 2015 is the year two-party politics ended.