Arlene Foster will tell the DUP annual conference today that Sinn Fein must decide if it wants to do business with her party or have direct rule ministers running Northern Ireland.
She will stress that the DUP supports a "balanced deal" not "a one-sided arrangement that rewards intransigent behaviour". Mrs Foster will tell delegates: "Northern Ireland needs a government and we cannot continue without ministers.
"Time is short and those in Sinn Fein blocking the restoration of local decision-making need to decide whether they want to do business with us or have direct rule ministers in place. I still believe that devolution is the best way to govern Northern Ireland but to do that in a way that delivers for all of our people we need serious partners in government."
The DUP leader will restate her pledge to legislate for the Irish language "in the context of legislating for the plurality of cultures that exist in Northern Ireland".
She will say: "The Irish language is spoken and enjoyed by thousands of people in all parts of Northern Ireland. It does no damage to the Union we cherish. I respect the Irish language and those who speak it.
"However, respect isn't a one-way street. Respect works both ways. It is time Sinn Fein started to respect our British culture.
"For too long they have shown nothing but disdain and disrespect for the national flag, the royal family, the armed forces, British symbols, the constitutional reality and the very name of this country".
Mrs Foster is set to accuse Sinn Fein of double standards.
"Republicans like to lecture us about rights. They're fond of rights now.
"They weren't so concerned about that most fundamental of rights - the right to life - during the Troubles. We are for rights. We respect rights. What we oppose is using the cloak of rights as a Trojan horse designed to break unionists," she will say.
Turning to Brexit, the DUP leader will say that listening to some people pontificate on it "you would be forgiven for thinking that life, as we know it, will end".
Mrs Foster will repeat the DUP's opposition to a hard border and its commitment to cross-border trade and the free movement of people "north and south for work, for education and as tourists".
She will also reiterate that while her party wants "a sensible Brexit", it won't accept special status for Northern Ireland.
The DUP leader will refer to her visit earlier this year to Our Lady's Grammar School in Newry.
"I came away with two things. A greater understanding of the genuine passion and love that many have for the Irish language and a beautiful gift of a framed picture. The picture was inscribed with the words 'Together we are strong'," she will say.
"Those words really registered with me. If we are to generate the opportunities for the pupils at Our Lady's and all the other schools across Northern Ireland to fulfil their potential then we have a far, far better chance if we are moving forward together."
Mrs Foster will conclude her speech with Belfast writer CS Lewis's quote, 'You can't go back and change the beginning, but you can start where you are and change the ending'.
"CS Lewis was right," she will say. "We cannot go backwards and undo what has been done.
"We cannot start again from somewhere different.
"We have to deal with things the way they are. But that doesn't mean the end is already written.
"We can shape a future for the next generation that is so much better than what we had to experience. Build a Northern Ireland where everyone can live a good life."