SACRAMENTO (AP) — Support is growing to end California's death penalty, but backers of an initiative on Tuesday's ballot still lack the majority needed to pass it, according to a Field Poll released Friday.

The survey found that 45 percent of likely voters support Proposition 34, which would end executions in favor of life imprisonment without parole, even for murderers already on death row. Thirty-eight percent oppose the measure, while nearly 1 in 5 voters remains undecided.

Support increased by 4 percentage points since a previous tracking poll was conducted in mid-October.

"They have a chance. It looks better than a few weeks ago because it's trending in their direction," said Field Poll Director Mark DiCamillo.

But he said supporters of the initiative need undecided voters to lean their way if the measure is to prevail. Historically, most late-deciders have tended to vote "no."

Pollsters found a majority of voters now believe that imposing the death penalty, with special inmate housing on death row at San Quentin State Prison and the cost of decades of legal appeals, is more expensive than life behind bars. That perception increased by 12 percentage points over the last year as Proposition 34 supporters make it a centerpiece of their campaign.

It's also a big turn-around from 1989, when a Field Poll found that 54 percent of likely voters said they thought life in prison cost the state more than sentencing someone to death.

California has spent about $4 billion to prosecute and incarcerate condemned inmates since capital punishment resumed in 1977, but just 13 inmates have been executed in that time. Critics say that is because death penalty opponents have deliberately engineered the legal system to be slow and costly.

The telephone survey tracked the changing views of 1,566 voters in two waves. Pollsters spoke with 815 likely voters from Oct. 17-24 and another 751 likely voters from Oct. 25-30. The overall survey has a sampling error margin of plus or minus 2.6 percentage points, with a larger margin for the smaller sample sizes.

In a similar Field Poll in September, more voters opposed Proposition 34 than favored it, but the trend has shifted since then, as those who want the death penalty repealed push their argument that imposing the ultimate punishment is simply too expensive.

They argue that the money could better be spent elsewhere, a message that pollsters say is evidently resonating with voters.

Support for the repeal was greatest among Democrats, those who classify themselves as liberal, Catholics and in the greater San Francisco Bay area. It was lowest among Republicans, conservatives, Protestants and voters in the state's inland regions.

Independent voters and moderates were split on the issue. There was considerable support for the repeal among blacks and Hispanics, although Asian-Americans were divided.

In the 1989 survey, two-thirds of respondents dismissed concerns that innocent people might be executed. In the survey released Friday, nearly half of surveyed voters think the innocent are executed too often.

"They certainly have a much better chance than I think most observers expected, given this state's long adherence to the death penalty," DiCamillo said of Proposition 34 supporters. "I must say, even I have been surprised."

Separately, pollsters asked the same likely voters their views on Proposition 32, which would ban unions from using payroll deductions to fund political activities.

They found dwindling support for the measure, which is generally backed by business groups and opposed by organized labor. Half of likely voters planned to oppose the initiative, while 34 percent were in support.

Support had slipped and opposition had grown since the September Field Poll.