More than 700,000 expected to vote in Northern Ireland Westminster election

Big focus will be on performance of DUP and Sinn Féin

More than 700,000 voters are expected to go to the polls in Northern Ireland on Thursday to decide which 18 MPs will be elected to the next Westminster parliament.

Voting takes place across the North amid uncertainty over whether the Conservatives will return with a clear majority or whether an advance in British Labour fortunes could result in a hung parliament thus giving Northern Ireland MPs some leverage on the key issue of Brexit.

But the greatest concentration is expected to be on how the DUP and Sinn Féin perform in the election.

Sinn Féin is hoping that the surge in support it experienced in the Assembly election of March will be maintained, thereby strengthening its demands for a Border poll on a united Ireland. In that election it came within one seat of the DUP and fewer than 1,200 votes short of the overall DUP vote.

Arlene Foster has urged unionists to rally behind the DUP to demonstrate to Sinn Féin that there is little or no prospect of a referendum on unity succeeding.

As the voters prepared to go the polls the leaders of the four main churches in Northern Ireland issued a statement of "hope and prayer" that the Northern Assembly would be reinstated in the talks that are to resume after the election. They urged politicians to "do their utmost to build bridges, overcome differences and find constructive ways forward to build on the peace which has been established".

More than 1,260,000 people are entitled to vote. In the March election the turnout was 65 per cent, leading to an expectation of a turnout on Thursday of 60 per cent or more. This would result in more than 700,000 of the Northern Ireland population casting their votes.

In the 2015 Westminster election the DUP polled best, winning eight seats, although it lost South Antrim to the UUP's Danny Kinahan; Sinn Féin was next with four seats although it lost Fermanagh South Tyrone to the UUP's Tom Elliott; the SDLP held its three seats; the UUP won two seats, a gain of two; and independent unionist Lady (Sylvia) Hermon was securely returned in North Down.

Six to eight of the 18 seats would be viewed as marginal while 10 are predictable. These are East Derry, North Antrim, East Antrim, Lagan Valley and Strangford where the outgoing DUP MPs appear certain to be returned.

Sinn Féin should win its outgoing seats of West Belfast, West Tyrone, Mid Ulster, and Newry and Armagh.

Lady Hermon will hold North Down

The biggest pressure is on the SDLP and the UUP. The DUP and Sinn Féin are targeting all their five seats. The SDLP's Margaret Ritchie appears particularly vulnerable in South Down where she is trying to see off the challenge of former Sinn Féin Minister Chris Hazzard. She will require unionists voting tactically to save her seat.

The DUP's Emma Little Pengelly in a campaign spearheaded by former DUP leader Peter Robinson believes she can unseat the SDLP's Dr Alasdair McDonnell in South Belfast while Sinn Féin's Elisha McCallion feels she has a chance against former SDLP leader Mark Durkan in Foyle.

Michelle Gildernew of Sinn Féin is aiming to regain Fermanagh South Tyrone from the UUP's Tom Elliott while the DUP's Paul Girvan is seeking to dislodge the UUP's Danny Kinahan in South Antrim.

A close contest also is envisaged in North Belfast, where Sinn Féin's John Finucane is challenging the DUP deputy leader Nigel Dodds.

In East Belfast Paddy Power bookmakers has placed Alliance leader Naomi Long the very narrow favourite at odds of 4/5 to defeat the outgoing DUP MP Gavin Robinson at odds of 10/11.

David Simpson is in a strong position to hold Upper Bann for the DUP but any aberrant division of the unionist and nationalist vote conceivably could give a chance to Sinn Féin's John O'Dowd or the UUP's Doug Beattie.