David Cameron launched his party's manifesto on Tuesday
A commitment to bringing forward a government paper to look at mechanisms for changing the corporation tax rate in NI is in the Tory manifesto.
Ulster Unionist Party leader Sir Reg Empey welcomed the manifesto launch by David Cameron on Tuesday.
A separate Northern Ireland version of the manifesto is expected to be published next week.
It is expected to set out policies on issues including a Bill of Rights and dealing with the past.
On Tuesday, Sir Reg said it "shows that only David Cameron and the Conservatives and Unionist have the leadership, vision and energy to deliver the change the United Kingdom, including Northern Ireland, needs".
In the UK version published on Tuesday, Northern Ireland is dealt with alongside Wales and Scotland in the section headed 'Strengthen the Union'.
In the section, it says: "The Conservative Party is passionate about the union and will never do anything to put it at risk".
The Labour manifesto, published on Monday, has stated that "we will continue to invest in the institutions of devolution, so that the Unionist and Republican traditions can work together for all the people of Northern Ireland".
The Northern Ireland version of the UCU manifesto is expected to set out policies on issues such as a Bill of Rights, dealing with the past and Presbyterian Mutual Society, as well as key devolved areas like health and education.
Meanwhile, the SDLP's Alasdair McDonnell has said planned Tory cuts "would result in the loss of between 1,600 and 2,000 public-sector jobs across the north".
He said: "We are going to face cuts no matter what the outcome of this general election, but there is no doubt that Tory cuts would be bigger and worse.
Later on Tuesday, the DUP's Arlene Foster said: "The Tories are promising us nothing in relation to Corporation Tax that the current government hasn't already done - the promise of a paper being published is meaningless."
"Only by electing a strong team of DUP MPs to Westminster can Northern Ireland's interests be defended."