The DUP has announced that Jonathan Buckley will be its candidate in the Lagan Valley constituency at the General Election – the seat currently held by former party leader Sir Jeffrey Donaldson.

Mr Buckley is an MLA in the neighbouring Upper Bann constituency.

Making the announcement in Belfast, interim party leader Gavin Robinson described Mr Buckley as the “next generation advocate” for unionist voters in the area.

He also repeated the call for unionist unity in the election, stating there were several seats that presented opportunities for co-operation with other unionist leaders.

Former party leader Donaldson has held the Lagan Valley seat for 27 years.

His lawyer announced this week that he would not be seeking re-election after he was charged with a number of historical sex offences, which he has indicated he will be contesting.

Mr Robinson said he knew there had been considerable interest in the Lagan Valley selection process as he confirmed that MLAs Emma Little-Pengelly and Paul Givan, who both represent the constituency at Stormont, would continue in their roles as deputy First Minister and Education Minister.

Let me say I am not parachuting anybody in

Announcing that Mr Buckley would run, he said: “With recent changes in Lagan Valley boundaries, almost 7,000 who were formerly in his Upper Bann constituency have now moved to Lagan Valley.

“Jonathan has strong links, including through family, to the Lisburn and wider Lagan Valley area.”

Mr Buckley said: “I am running in Lagan Valley because I am putting country first.

“I am running in Lagan Valley to ensure pro-union voters can unite behind a candidate and ensure Lagan Valley has strong representation at Westminster.”

The DUP is expected to face stiff competition in the constituency from Sorcha Eastwood from the cross-community Alliance Party. The Ulster Unionist Party is also running a high-profile candidate through its deputy leader Robbie Butler.

Mr Robinson rejected any suggestion of criticism that his party was running a candidate who does not represent Lagan Valley at Stormont.

He said: “Let me say I am not parachuting anybody in.

“Johnny, along with the 7,000 individuals that he represents in Upper Bann, have been moved outside of their choice through Boundary Commission changes.

“All our constituencies are different and people recognise that.

“So, if Johnny is a blow-in and any candidate in Lagan Valley would like to suggest he is, then they are dismissing the 7,000 that are walking with him.

If other parties can't see beyond themselves, if other parties can't bring themselves to set aside person for country, then that is a matter for them

“They are in Lagan Valley together. He is standing with the people he represents today as their candidate for Westminster in Lagan Valley.”

Mr Robinson said he believed that unionist unity was something which resonated strongly with voters.

However, other unionist parties in the region, the Ulster Unionists and the Traditional Unionist Voice, have said they are not interested in electoral pacts.

Mr Robinson sad: “Whilst I will do what I can to respect and honour the wishes of the people we have the privilege of representing, if other parties can’t see beyond themselves, if other parties can’t bring themselves to set aside person for country, then that is a matter for them.

“But that gives the people a choice and it is a choice I know in previous elections they have made strongly of their own view that if the parties can’t do it then they can, they will plump for those that stand up and speak out for Northern Ireland positively and powerfully.”

The party also announced that Belfast City councillor Tracy Kelly would be the candidate in the Belfast South and Mid Down constituency.

Mr Robinson also confirmed that all of the party’s seven current MPs have been reselected.