The DUP leader will make a call for closer co-operation between unionist parties ahead of next May's assembly and council elections.

In what is the most anticipated speech of his political life, Gavin Robinson will tell his party conference "we must not gift wrap seats to Sinn Féin and Alliance".

The DUP believes that in constituencies like Lagan Valley and North Antrim the split unionist vote has handed seats to its opponents unnecessarily.

But such calls have fallen on deaf ears before and with the DUP apparently weakened there is no guarantee that won't be the case again.

Robinson will say the DUP "will not be found wanting" when it comes to co-operation to maximise the pro-unionist vote.

He is expected to tell delegates: "I am committed to working constructively and engaging again with other unionist parties, as we have before, to secure the election of the largest possible number of pro-union candidates to the assembly and our councils.

"Working together, we are stronger. With serious intent, we can work closely to secure sensible outcomes.

"We can collectively encourage voters to give their preference votes to pro-union candidates and ensure that constituencies and electoral areas are not flooded with candidates from unionist parties.

"I am not asking anyone to give up what they believe.

"I am asking that, collectively, we do not gift wrap seats to Sinn Féin, the SDLP or Alliance that unionism could otherwise win."

While not ruling out co-operation with other unionist parties the new Ulster Unionist Party (UUP) leader Jon Burrows has often spoken of his ambition to return his party to its former position as the largest unionist party.

Traditonal Unionist Voice (TUV) leader Jim Allister has frequently said he is open to co-operation, but he also accused the DUP of betraying unionism by returning to Stormont and accepting post-Brexit trading arrangements that effectively partition the United Kingdom.

Any talks between the three unionist parties could be fraught with difficulties.

On immigration, Robinson is expected to say people's fears should not be dismissed.

He's likely to say that "controlling immigration is not extreme; and expecting people to respect our laws and play their part is not extreme either.

"Our immigration system must work for the people who live here.

"Fairness is not intolerance. Common sense deserves a voice; and we will be that voice."

There's little doubt which party goes into next May's Stormont Assembly election under the most pressure.

For the hard-pressed DUP, the blows keep coming.

First the party knows the stigma of its former leader Jeffrey Donaldson's conviction for child sex offences, including rape, is likely to cost it votes with a sceptical unionist public.

Next there's a twin threat from a possibly resurgent UUP under its energetic new leader Jon Burrows, as well as the constant threat from Jim Alllister's TUV.

Then there's its attempt to scramble after President Trump's call for a United Ireland - a man of course who, at least until that point, had many fans among the DUP's elected representatives.

All off this on top of a difficult general election when the party lost three seats - North Antrim, Lagan Valley and South Antrim.

For party leader Robinson - thrust into the position after Donaldson's sudden and dramatic fall - the big test is coming.

Perhaps that's why his speech is expected to call for inter-unionist co-operation.

But he is speaking from a position of relative weakness and the DUP's opponents undoubtedly smell blood.

You can watch and follow Gavin Robinson's speech live on the BBC News NI website from about 12:30 BST.