John Kerry's (search) campaign says it believes federal law bars him from tapping any of his wife's vast Heinz fortune for his presidential campaign, removing an arsenal of cash that some Democrats hoped he could use to counter President Bush's fund-raising prowess.

Teresa Heinz Kerry's (search) holdings have been estimated at $550 million or more, putting her among the 400 richest Americans on Forbes magazine's list last year.

Federal campaign law stipulates that assets solely under the control of Heinz Kerry, including those reported on her husband's recent Senate disclosure form, can't be used for the Massachusetts Democrat's presidential campaign, campaign spokesman Robert Gibbs said.

Bush is expected to raise a record $200 million or more for his re-election bid. Kerry raised about $7 million from January through March, the most recent figures available.

Kerry reported investments valued at about $700,000 to $2.4 million. Two of his advisers, who spoke only on condition of anonymity, said Kerry has several million dollars — they wouldn't specify further — of his own money he could tap during the primary or if he wins the Democratic nomination.

"The law that says a candidate cannot use the assets of a spouse has governed every election since the regulations went into effect Aug. 25, 1976," Gibbs said Wednesday.

"Senator Kerry is a man of some significant wealth who could make, if he chose, a sizable investment in his presidential campaign," Gibbs said. "I do not believe we have ever left anybody with the impression that we would be spending several hundred million dollars."

The Massachusetts senator is mum about what assets he hasn't reported and has not yet disclosed income tax returns traditionally released to the public by most presidential candidates. Kerry hopes to release the returns at some point, Gibbs said.

In the past, when asked whether Kerry would tap the Heinz fortune for the race, the Kerry campaign has said it might use it if the couple faced personal attacks.

Experts said the decision not to tap his wife's fortune erases any perception that the vast personal fortune elevated his candidacy, particularly among donors, by making him a more attractive Democratic rival to the well-funded Bush.

"The big impact is if he could have simply spent two or three times as much as any of his opponents on the primary that would have given him a huge advantage in a divided field," said Michael Malbin, executive director of the Washington-based Campaign Finance Institute (search). "That won't be his situation now."

The Senate financial disclosure form Kerry filed last month details the wealth of Heinz Kerry, the widow of Pennsylvania Sen. John Heinz III (search) of the Heinz food dynasty.

But the report gives only sweeping ranges of investments' value; income and assets for Teresa Heinz Kerry were at least $210 million, with several investments identified only as worth more than $1 million.

The same report shows Kerry with investments valued at about $700,000 to $2.4 million, including two investments he holds with his wife: a painting worth $250,001 to $500,000 and bank accounts worth $50,001 to $100,000.

Federal Election Commission officials said that while they couldn't make a formal ruling unless they get a request, their initial reading of the law was that Kerry couldn't use his wife's assets for his presidential race. They noted, however, that they examine all details in a particular case before reaching a formal conclusion.

Under the federal rules, a spouse is limited to the same $2,000 individual donation limit as other campaign contributors. Heinz Kerry cannot transfer money or other assets to Kerry for the purpose of influencing a federal election. For example, if Kerry were to use gifts from her to help finance his race, he would have to show they were part of a pattern of giving that predated his candidacy.

In most cases, Kerry could use half the value of any jointly held property on the race. One exception is joint bank accounts, which the FEC has traditionally let candidates tap in their entirety.

The Senate disclosure form doesn't list any of the homes Heinz Kerry or Kerry own. Heinz Kerry has said she owns at least four — in Pittsburgh, Nantucket, Mass., the Georgetown section of Washington, and Idaho. Kerry and Heinz Kerry own at least one house together: a $7 million residence in Boston.

An Associated Press review of property records did not identify any residences that listed Kerry as sole owner.

Gibbs declined to comment on the couple's real estate or other possessions, including whether any of Heinz Kerry's property has also been put in Kerry's name.

It's too late for Heinz Kerry to transfer assets to Kerry that he would then use in his campaign, said Larry Noble, a former FEC general counsel who is now executive director of the Center for Responsive Politics (search), a nonpartisan campaign finance watchdog group.

"I think it would be virtually impossible at this point for him to show it's unrelated to the campaign," Noble said.

Though Heinz Kerry can only give $2,000 to Kerry's primary campaign, her wealth could still find its way into the race.

For example, she could give a large sum to an outside group that could spend the money on Kerry's behalf; the group's expenditure would have to be independent of Kerry's campaign. Heinz Kerry also could pay for ads on her behalf if she feels she has been attacked in the race.