Prime Minister John Key has confirmed welfare reform, focused on young people, will be announced as National Party election policy tomorrow.



Delegates have this morning gathered at the Wellington Town Hall for the annual conference, which doubles as a celebration of the 75th anniversary of the party.



Key said his centrepiece speech tomorrow would focus on welfare reform, particularly in relation to young people.



"When young people go on welfare they stay there longer," Key said.



"What we're doing for young people in the welfare system is not working."



In his speech this morning, Finance Minister Bill English said in a growing economy "we will need everyone who can work to be in work".



"Unemployment among those aged 25 and over is already down to 4.5 per cent, with an ageing population leaving the workforce in increasing numbers," English said.



"The Prime Minister will talk more about those policies tomorrow - better welfare policy is as important for our economy as it is for our community."



English said a re-elected National Government would focus on growing the tradeable sector.



"National will lock in and extend the policies we initiated in the last three years. ... We will persist on limiting government debt, to keep our interest rates lower for longer and to reduce our reliance on foreign lenders, and to build a buffer against future economic shocks," English said.



He did not release any new policy, instead pointing ahead to the "next few months" for further announcements in the run-up to the election.



Key said National supporters could not take the party's poll ratings for granted.



"Yes, the polls are good for now but polls go up and down," he said.



"We can't leave anything to chance, we have to redouble our efforts."



Voters would face "a very clear choice" in the November election. A Labour-Greens Government would be backward looking and take the country back to the "bad old days" of borrowing and spending.



"They believe in the politics of envy," Key said.



The National-led Government had been through a difficult three years, he said.



"I'd be surprised if a Government has ever had as much thrown at it as we have in the last three years."



Key joked that he had given Finance Minister Bill English one task this year - to get New Zealand's credit rating equal to the United States.



The US credit rating was last week downgraded to AA+ by Standard and Poor's.



English got one back at Key in his speech, however, joking that he had got New Zealand's credit rating equal with the US quicker than Key had caused New Zealand to catch up with Australia.



The conference continues.