MPs have voted in favour of a general election for Thursday 12 December, the first winter election since 1923.

With four parties polling over 10%, this election looks set to be one of the most contested and unpredictable for many decades.

For the Conservatives, their aim will be to regain the majority they lost at the last election under Theresa May. To do this, they need to win Labour seats that voted Leave in the EU referendum, such as Blackpool South, Stoke-on-Trent North and Dagenham and Rainham.

However, in order to achieve a majority, they need to fight off possible losses from both the SNP and the Liberal Democrats.

In Scotland, the Conservatives could lose seats like Stirling and Gordon to the Scottish nationalists, and could lose Remain-voting seats like Southport, Cheltenham and Winchester.

Things may not be much better for Labour. Not only will they have to defend against potential losses to the Conservatives, the Liberal Democrats will be looking to take seats like Bermondsey and Old Southwark, Vauxhall and Cambridge, and the SNP will be eyeing close seats like Kirkcaldy and Cowdenbeath, East Lothian and Glasgow North East.

Then, there are marginal seats between Labour and the Conservatives, such as Ipswich, Thurrock, Calder Valley and Kensington, which could shift with larger vote shares for smaller parties like the Liberal Democrats and the Brexit Party. Peterborough, a seat won by Labour in a close by-election, will also be one to watch.

Finally, what will be the bellwether seat to scrutinise? Watford, a narrow Leave seat, a Labour-Tory marginal, and one of the only towns with a Liberal Democrat mayor, will be an important one to watch – it has reflected the final result every election since February 1974.