Launching its manifesto, the party again ruled out taking part in any future coalition.
However, it said it would be prepared to support a party whose proposals would be in the best interests of Northern Ireland and the UK in general.
It calls for a budget settlement to enable real increases in health and education spending over five years.
On welfare, the DUP wants the abolition of the spare room subsidy also known as the bedroom tax.
The party wants air passenger duty abolished because it says it has a disproportionate impact on regions farthest from the south-east of England.
It wants guaranteed access from Northern Ireland to London's hub airports and a feasibility study into a tunnel or enclosed bridge between Northern Ireland and Scotland.
Party leader Peter Robinson said:  "After the election we are prepared to support either the Conservative Party or the Labour Party if the circumstances are right;  or for that matter neither if the circumstances are not right.
Main pledges
Policy guide: Where the parties stand
"And secondly, the price for DUP support in the new Parliament cannot simply be summarised and dismissed as more money for Northern Ireland.
"I believe that delivery of The Northern Ireland Plan can help redefine our place within the United Kingdom.
"So whilst we could well play a pivotal role in the next Parliament, we have a sense of perspective about our size and our capacity to dictate policy at a national level.
"While our influence in the national context will be limited by our size and the wider post-election arithmetic, we would contend that whatever the final Commons headcount we could be in a key position to bring real and substantial change to Northern Ireland."
Other policies
The DUP has said it believes its votes could be vital in the formation of the next UK government.