The DUP leader has told his party conference that the Irish presidential campaign shows there is "institutional intolerance" of Protestant cultural heritage in the Republic of Ireland.
Gavin Robinson referred to media coverage of Fine Gael presidential candidate Heather Humphreys in his keynote speech.
Mr Robinson said questions raised about her husband's links to the Orange Order in Co Monaghan showed the depth of the problem.
He said the fact that the Orange Order links have been raised in the media showed that there was "institutional intolerance of Protestant cultural heritage".
"The Irish Republic is a country where candidates for their highest office in that country are vilified because of their religion and their family’s connection to the Orange Institution," he said.
Mr Robinson also criticised the Irish's Government input into yesterday’s joint legacy announcement for Northern Ireland.
"Rather than challenging Dublin on its failure to investigate its own sinister role in our troubled past - the UK government seems to want to placate them," he said.
"To hand them even greater influence over legacy cases. And all while the Irish Government takes them to court.
"It would be laughable if it weren't so serious."
He told delegates predictions of a border poll by 2030 would not happen. But he told the conference the party could not afford to be complacent.
He said the Stormont Assembly had to work and people had to see the tangible benefits of a devolved government in their everyday lives.
He said DUP ministers in the Executive were delivering on things like childcare and winter fuel payments.
He said Sinn Féin ministers were failing to deliver important road maintenance and building projects and focusing on issues like Irish language signage for Belfast’s new £340m bus and rail station.
The most sustained applause of the afternoon was reserved for a reference to transgender terminology.
Mr Robinson said his party took the view "that a boy is a boy and a girl is a girl".
"That is not prejudice, that is not intolerance. That is truth."
He said while the DUP would show respect for every individual it did not mean "surrendering to ideology that we believe is harmful to the individual and to society".
