Republican presidential nominee John McCain unveiled $52 billion in new economic relief measures Tuesday that are aimed at helping the unemployed, seniors and others stressed by the recent sharp downturns in the stock market.

Speaking at a campaign rally in Pennsylvania, McCain also promised to require the Treasury Department to guarantee 100 percent of all savings accounts for a six-month period.

The Arizona senator’s Pension and Family Security Plan would eliminate taxes on unemployment benefits for those making less than $100,000 annually. It also seeks to lower taxes for seniors who have been recently forced to sell their stocks at a loss as well as those who have had to tap their retirement accounts. Additionally, the plan would halve the capital gains tax on stock profits to 7.5 percent for two years.

“It’s a plan that would broadly benefit the economy and would put cash into the hands of those damaged by the stock market,” McCain economic adviser Douglas Holtz-Eakin said in a conference call with reporters. “It would stabilize some of the financial insecurity we see.”

The plan would help individuals forced to sell their investments at a loss by increasing the amount they can deduct on their taxes from $3,000 to $15,000 for the next two years.

McCain also proposed lowering the tax rate for retirees withdrawing from their IRA and 401(k) accounts to 10 percent in 2008 and 2009. According to the campaign, the policy will apply to the first $50,000 withdrawn from these accounts each year and will affect the nearly nine million Americans over the age of 60.

“Investors are always responsible for their investment decisions, but the hard earned savings of Americans should not be penalized by the erratic behavior of politicians,” McCain told supporters at a rally in Blue Bell, Pa. “My plan is intended to create jobs and increase the wealth of all Americans.”

Last week, McCain called for suspending a requirement that forces retirees to withdraw their retirement savings accounts after the age of 70 and a half — a measure also endorsed by his Democratic rival, Sen. Barack Obama. On Monday, Obama proposed nearly $60 billion in new measures aimed at stemming the economic crisis.

Obama’s proposal would offer tax credits to encourage job creation, loosen rules on retirement savings withdrawals and expand federal lending to state and local governments. Obama also called for a 90-day foreclosure moratorium for certain homeowners.

That plan was criticized by McCain and his advisers, who insisted that it would result in higher taxes.

“Barack Obama had the opportunity even yesterday to say, ‘gee, the economy is weak, I want to help it,’” Holtz-Eakin said. “But he didn’t do the one thing he could do to relieve pressure on jobs, which is to drop his plans for higher taxes and expensive healthcare mandates.”

The Obama campaign responded with a statement attacking the McCain proposals as “trickle-down, ideological recipes” that would do little to improve the economy.

“John McCain’s latest gambit is a day late and 101 million middle-class families short,” Obama spokesman Bill Burton said in a statement. “McCain’s plan would spend $300 billion to bail out the same irresponsible Wall Street banks that got us into this mess without doing anything to help jumpstart job growth for America’s middle class.”

The candidates will face off for the third and final presidential debate Wednesday at Hofstra University in New York. The debate, which will focus on economic policy and domestic issues, will be moderated by Bob Schieffer of CBS News.