DUP leader Peter Robinson has told his party's annual conference that hardline unionists opposing his power-sharing government with Sinn Féin are "cave-dwellers" who wish to impose Dublin rule on the North.

Robinson strongly defended his party's record at Stormont and while he declined to set out a timetable for the devolution of policing and justice, he said the DUP supported the move in principle.

In a stinging attack on Jim Allister's Traditional Unionist Voice, Robinson claimed it wanted to destroy everything the DUP had achieved and would lead unionism into "powerlessness and irrelevance" with "an ever greening" of the political agenda.

The TUV took a huge slice of the DUP vote in June's EU election but Robinson claimed it was engaged in "fantasy politics" whereas his party inhabited "the real world".

The DUP leader lambasted those with "ill-disguised bitterness and malevolent intent" who would take the North back to "the dark and dismal past". That "wouldn't just be mad – it would be bad and wicked beyond belief".

It would "knowingly consign future generations – our children and grand-children – to more of the same violence and uncertainty that would inevitably follow renewed political instability and conflict".

Robinson denied the DUP had betrayed its principles. He said it was easy to always say no and live on "the fruits of opposition" whereas his party had made hard choices and risen to the challenges of government.

The only alternative to power-sharing at Stormont was joint London-Dublin rule, he claimed. He believed the DUP's electoral difficulties were in the "rear view mirror" and that May's Westminster poll presented no problems.

Robinson said the British had inflicted a "military defeat" on the IRA, bringing Sinn Féin to the negotiating table.

The DUP had a veto at Stormont and was in control of events: "We have our hand on the steering wheel and, when we need, we can apply the brake."