Northern Ireland joined the European Union as one and must either "leave as one or remain as one", Steve Aiken said as he was formally elected as new leader of the Ulster Unionist Party.
Mr Aiken, the only candidate, was elected leader by the party's ruling body, the Ulster Unionist Council, at a meeting in Co Antrim on Saturday, succeeding Robin Swann.
In his first speech as leader, the South Antrim MLA attacked the DUP, sought to galvanise Ulster Unionists for the challenge of the Westminster general election on December 12th, provide assurances on the union, and - deploring Boris Johnson's Brexit deal - insist there must be no border down the Irish Sea.
Mr Aiken told delegates that they must be in no doubt that this is a “Brexit election” and they should not be “DUPed” into believing that in some way the union will be “saved by their antics”.
“The stark reality, as we told them time, and time, and time again, was once that ‘regulatory’ border was conceded it was never going to be taken off the table,” he added.
"If the Conservatives deal goes through, Northern Ireland will, well and truly, be a 'place apart' - we will be separated from our largest market, with differing legal systems, tax regimes, and held 'accountable' by special and joint EU committees," he said.
Added Mr Aiken, "There are many unionists, and indeed many in this room, who will have voted to leave, but I'm pretty sure you didn't vote for England, Scotland and Wales to leave, while Northern Ireland stays - we have a stark choice, but for us, the union, of our whole United Kingdom, must come before anything else."
"So, for the Ulster Unionist Party, our message is clear - with only Boris's/DUP sell-out deal on the table, we must put our union first. We joined the EU as one, we either leave as one, or we remain as one," he added.
Mr Aiken was scathing of the DUP, accusing the party of “gross incompetence in agreeing a regulatory border down the Irish Sea”, of “miring of the good name of unionism and Northern Ireland in an alphabet soup of scandal, coupled with their inability to help restore our local assembly”.
He complained of "Sinn Féin's constant attempts to prevent the restoration of Stormont, linked to trying, at every opportunity, to besmirch the memory of our brave security forces - all the while hypocritically attempting to rewrite history".
“If republicans want to claim that they were fighting a war then let them accept and admit that their actions were war crimes,” he said.
Expressing opposition to the proposed Historical Investigations Unit Mr Aiken said he would never acquiesce “to “legacy witch-hunts” against former member of the RUC and British army.
Mr Aiken said the party would resist the push for a Border poll and also took a swipe at Taoiseach Leo Varadkar and Tánaiste and Minister for Foreign Affairs Simon Coveney.
“We have to constructively and vigorously engage, countering at every opportunity ‘civic nationalism’s’ narrative that we are all headed for an ‘’agreed Ireland’,” he said. “We will not be reticent in putting the case for the union strongly forward - whether by putting Leo and Simon right or their less than tactful pronouncements, to making sure that nobody forgets that the clear majority of people in Northern Ireland are more than happy with the union.”
He said that “when hospital waiting lists and the welfare of our disadvantaged take a lower priority” than Sinn Féin’s “New Ireland” that “even in the toxic atmosphere of this election we could never leave those who believe in the union to a Sinn Féin MP”.
After his speech he justified the party's decision to give Nigel Dodds a free unionist run against Sinn Féin's John Finucane in North Down notwithstanding his vigorous criticism of the DUP, and despite initially saying the UUP would contest all 18 Northern Ireland constituencies.
He said he had listened to the opinions of party members, particularly those from North Belfast, and their "biggest concern" was that unionism would have no representation in Westminster from the constituency.
“Let’s be abundantly clear. Sinn Féin abstentionist MPs could have either put a halt to Brexit or slowed it down. They never bothered taking their seats. They are not an anti-Brexit party, they are not a pro-union party, they are just abstentionists,” he told reporters.