These are the constituencies that could decide the general election

In the run-up to the General Election on 8 June, MPs are battling for seats each of the UK’s 650 constituencies.

But the eyes of party strategists are focused sharply on the ‘marginal constituencies‘: the places where the vote was closest in 2015, and where power is most likely to be snatched from a rival.

There is no official metric that decides exactly what makes a seat marginal, but a gap of 10% or less between the vote share for the winner and the runner-up is held to be a decent indicator.

And a number of constituencies have margins much tighter than that.

In Gower, South Wales, Conservative MP Byron Davies squeezed into power with a majority of just 27 votes – a margin of just 0.1%.

These are the 10 constituencies with the tightest margins, where power is most likely to change hands.

At the other end of the scale sit the ‘safe seats‘, where one party holds a massive majority that is unlikely to be dented.

The majorities here can be hundreds of times larger than in the most marginal seats, and are generally not viewed as ket battlegrounds by politicians.

The largest majority in 2015 was achieved by Labour’s George Howarth in Knowsley. He won 34,655 more votes than his closest rival.

The second largest majority was also a Labour seat: Stephen Timms achieved 34,252 more votes than the runner up in East Ham.

Party leaders and key members often stand in safe seats, where they can be confident of avoiding an ousting.

Theresa May had the fourth largest majority of any MP in 2015 with 29,059, and Jeremy Corbyn had a comfortable buffer of 21,194.