Sun Life Financial released the latest installment of its Unretirement Index on Tuesday, showing 80% of Americans believe it'll take at least three years to rebuild their nest eggs. More disturbingly, 20% believe they will never fully rebuild their savings.

More than half of respondents still working believe they'll have to work three years beyond their planned retirement date. One-quarter of respondents say they are confident they will be able to take care of medical expenses in retirement, and 42% are confident they can afford basic living expenses.

“Our latest Unretirement Index shows that American workers have surveyed the damage of the economic crisis and are coming to grips with how long it will take them to rebuild their savings and how long they will need to remain in the workforce in order to do so,” Wes Thompson, president of Sun Life Financial U.S., said in a press release.

In line with the general atmosphere of upheaval surrounding the upcoming elections, 51% of respondents said they plan to vote against the incumbent, regardless of party affiliation. Respondents' confidence in public programs is at a "new low," according to the report. Just 14% are confident in Social Security and 16% are confident in Medicare. Employer benefits are still the greatest source of confidence, but still low at 22%.

Despite 71% of respondents saying they are reducing their spending, 23% are not saving at all for retirement. Two-thirds of respondents say they are reducing their debt.

The report noted that respondents in their 30s are especially pessimistic. Sixteen percent say they'll have to work more than 10 years beyond their estimated retirement date; 87% say they'll do so in order to "earn enough money to live well," more than any other reason. Sixty percent say they are "not at all confident" they'll receive the same level of benefits from Social Security that today's retirees receive.