The 2019 General Election is likely to see the nations and regions of the UK behave in very different ways, with parties performing strongly in one area but poorly in another. Here is a snapshot of the state of play around the country.
The Conservatives are on the defensive in south-west England. This is one of the Lib Dems' main target areas, with the party hoping to take up to a dozen seats ranging from St Ives (which needs a tiny 0.3% swing to change hands) to Chippenham (14.6%).
The Tories will need to watch out for Labour as well, who are targeting places like Swindon South (which would fall on a 2.4% swing), Filton & Bradley Stoke (4.2%) and Gloucester (5.1%).
South-east England is one part of the country where relatively few constituencies could change hands, but there are still some high-profile contests. Labour are eyeing Hastings & Rye, the former seat of ex-Tory minister Amber Rudd, while the Tories will want to retake Canterbury - one of Labour's surprise gains in the 2017 election.
Dominic Grieve, another former Conservative and now standing as an Independent, is hoping to hold on to his seat in Beaconsfield.
In London the Conservatives are facing a pincer movement from both Labour and the Liberal Democrats.
Labour are targeting Theresa Villiers in Chipping Barnet, Iain Duncan Smith in Chingford & Woodford Green, and the Prime Minister himself, Boris Johnson, in Uxbridge & Ruislip South. Hendon, Putney and Harrow East are also in play. Meanwhile, the Lib Dems could take as many as four seats from the Tories: Richmond Park, Finchley & Golders Green, Cities of London & Westminster and Sutton & Cheam.
There could be a lot of churn in the East Midlands, with both the Tories and Labour targeting around half a dozen of each other's seats. Both parties are also eyeing Broxtowe, where ex-Tory Anna Soubry will be standing for the Independent Group for Change.
Labour will be on the defensive in the West Midlands. This is one region where the Conservatives will be looking to offset losses elsewhere in the country, in the shape of seats like Newcastle-under-Lyme (which would fall on a 0.1% swing), Warwick & Leamington (1.2%) and Wolverhampton South West (2.6%).
Labour are vulnerable in two urban seats in Eastern England, Ipswich and Bedford, both of which are Conservative targets.
The Tories are also hoping to take Norfolk North, seat of the retiring Lib Dem MP Norman Lamb. Thurrock and Norwich North are marginal seats currently held by the Conservatives, and the kinds of places Labour will need to take if they hope to do well in the election.
North-east England is a Conservative-Labour battleground.
Up to seven Labour seats could be at risk, ranging from Bishop Auckland, which would fall to the Tories on a 0.6% swing, to Blyth Valley (9.3%).
By contrast there is only one seat (Middlesbrough South & Cleveland East) which Labour might take from the Tories. Hartlepool - a Labour seat since its creation in 1974 - is the sort of seat likely to be targeted by the Brexit Party.
Another Conservative-Labour battleground is north-west England.
The Tories will be looking to make big gains here. Crewe & Nantwich, Warrington South, Blackpool South and Weaver Vale are among a host of seats Labour need to defend. The Tories will also be looking to safeguard their own marginal seats, such as Bolton West and Pendle.
Yorkshire & the Humber
In Yorkshire & the Humber, the Lib Dems, Labour and the Tories are all hoping to take Sheffield Hallam, previously held by the Independent (ex-Labour) MP Jared O'Mara.
Labour will be on the defensive in the likes of Keighley, Colne Valley and Wakefield, all of which are high on the Tory target list.
In Scotland it is the SNP who will be hoping to make the largest number of gains, with up to 20 seats in their sights.
Conservative, Labour and Lib Dem seats are all at risk, and this is one part of the UK that could see a huge turnover of MPs.
Not all of the SNP's own seats are safe, however: in Fife North East the party is defending a single-figure majority of two votes over the Liberal Democrats.
Wales offers opportunities for all the main UK parties, as well as Plaid Cymru.
The Tories probably have the best chance at making gains, such as Wrexham (which would change on a 2.7% swing), Vale of Clwyd (3.1%) and Gower (3.6%) - all Labour seats.
Labour could in turn pick up Preseli Pembrokeshire from the Tories on a 0.4% swing, and Arfon from Plaid Cymru on a 0.2% swing.
Plaid Cymru is hoping to take Ynys Mon from Labour, while the Lib Dems could take Ceredigion from Plaid Cymru.
The main parties in Northern Ireland are all hoping to make gains from each other.
Sinn Fein is targeting Belfast North from the DUP; the Alliance Party is hoping to win Belfast East from the DUP; the DUP is aiming to defeat the Independent Sylvia Hermon in North Down; the Ulster Unionists are hoping to take Fermanagh & South Tyrone from Sinn Fein; and the SDLP is hoping to take Belfast South from the DUP.