The Conservative government will move to impose term limits on new, unelected senators, CTV News has learned.

The changes will be included in a wider package of democratic reforms, such as fixed terms for federal elections.

Currently, senators can sit until age 75, although until 1965, their appointments were for life. Under the Conservative proposal expected Tuesday, that will be restricted to eight years.

The prime minister appoints senators. Alberta and B.C. have legislation to hold elections for senators, although the previous Liberal government did not appoint the senators-elect.

Asked when there would be a full elected Senate, CTV's Ottawa bureau chief Robert Fife said: "Somewhere before hell freezes over."

Changing the Senate to an elected model would require a constitutional amendment, with at least seven provinces representing at least 50 per cent of the population signing on, he said, adding, "no one wants to open that basket of crabs."

Ontario and Saskatchewan would like the Senate abolished, he said.

Asked why Prime Minister Stephen Harper might be making these changes, Fife said to get the ball rolling on reforming the institution, but "he's also sending a very subtle message to the Liberal-dominated Senate -- if they obstruct his government's agenda, he'll go to the people to get a mandate to force constitutional change."