The Conservatives are the only party that can be trusted to transfer corporation tax powers to Northern Ireland after the general election, Theresa Villiers has insisted.
Addressing party faithful in Belfast at the launch of the Tories' manifesto for the region, the Northern Ireland Secretary questioned Labour's commitment to the handover of the rate-setting responsibility.
The coalition government passed legislation to enable the devolution of the power from Westminster to the Stormont Executive in the final weeks of the last parliament.
But the next government will have to trigger a commencement clause to formally transfer the key tax varying responsibility to Belfast.
The Tories have pledged to give the green-light, as long as the Executive can demonstrate it is on a firm financial footing.
Ms Villiers today claimed Labour had been silent on its intentions if it got into Downing Street.
"Devolution of corporation tax was conspicuously absent from Labour's 102-word manifesto for Northern Ireland published earlier this week," she said.
"So the message is clear - only the Conservatives can be trusted to deliver corporation tax powers for Northern Ireland - a potential economic game changer that could create thousands of jobs and opportunities for people here."
Labour did not oppose the passage of the legislation through parliament.
Politicians in Northern Ireland lobbied strongly for the power to set their own rate for the tax businesses pay on their profits. The majority want to reduce it from the current UK rate of 20% to somewhere around the 12.5% levied in the Irish Republic, claiming it will greatly enhance the region's competitiveness with its neighbours south of the border.
Any reduction in the rate will see a proportionate cut from the block grant Northern Ireland receives from the Exchequer each year. Critics of a rate reduction claim spending on public services will be hit to fund a tax break for big businesses.
The Conservatives are running candidates in 16 of Northern Ireland's 18 constituencies. More than half of their candidates are not based in the region.
In a foreword penned for his party's Northern Ireland specific manifesto, Prime Minister David Cameron said his was the only "major" UK party running candidates in the region.
"Northern Ireland can play a key role in ensuring that the United Kingdom stays on the path away from austerity and towards greater prosperity," he said.
"It can do this by returning Conservatives from Northern Ireland to help secure a majority Conservative government in Westminster.
"At this election, the Conservatives are the only national party that is sufficiently committed to Northern Ireland to put up candidates here.
"We are the only major party that offers Northern Ireland the opportunity to participate fully in the politics of the United Kingdom."
Ukip is standing candidates in 10 constituencies in Northern Ireland.
At the manifesto launch in the party's new office building in Belfast city centre, Ms Villiers insisted the Conservatives would never be neutral on the Union and vowed to work to ensure the four nations remained together.
Ms Villiers also hailed December's Stormont House Agreement between the British and Irish governments and the five Executive parties on a range of outstanding political wrangles.
The fate of the deal and, as such, the devolution of corporation tax powers, depends on the successful resolution of an ongoing impasse between Sinn Fein and the Democratic Unionists over the implementation of welfare reforms in the region.