The Traditional Unionist Voice (TUV) will “continue to beat the drum” against the Irish Sea border, Jim Allister will say later.

The party leader will make his remarks at his party’s annual conference, which is taking place in Cookstown on Saturday.

Members will gather for the first time since Allister got elected to Westminster, after he won the North Antrim seat from Ian Paisley of the Democratic Unionist Party in the general election in July.

Speaking ahead of the conference, Allister said there would be an “upbeat spirit”, however, he will warn that unionism will not recover “unless and until” the Irish Sea border is fully removed.

The Brexit deal for Northern Ireland, the Windsor Framework, effectively keeps it inside the EU single market for goods.

That creates the Irish Sea border, a range of rules and processes required to send goods from Great Britain to Northern Ireland.

When the EU makes new rules for goods they will generally apply in Northern Ireland which in turn can make the operation of the Irish Sea border more complicated.

In December, the UK government said the Windsor Framework was “the only available and credible” basis for stability in Northern Ireland.

But Allister is expected to say that under the current arrangements the union is “diminishing day by day”.

“As someone who cares about that union and wants to bring strength, not weakness, to that union, then of course, that is my primary focus, and will continue to be,” he will say.

He is expected to call for a “more practical and visible cooperation” in a unionist caucus of parliamentarians who are dedicated to “upending the protocol” and all its ramifications.