Rival Steve Forbes accused Bush, the Republican presidential front-runner, on Friday of breaking a no-new-taxes pledge. Bush denied it and said his record of cutting Texas taxes by about $3 billion speaks for itself.

"I'm saying I cut the taxes. The implication is I tried to raise taxes. I cut taxes," Bush said.

At the heart of the controversy — and a new television commercial being aired by Forbes — is a 1994 written statement given to the Houston-based group Taxpayers for Accountability during Bush's first race for governor.

That statement, bearing what appears to be Bush's signature, said: "I, George W. Bush, candidate for the position of governor, pledge to oppose any legislation establishing a state personal income tax or increasing the sales tax." Campaign officials have said they don't know where the signature came from, although they believe it was produced by an automated pen.

"We can't determine the exact circumstances" under which Bush responded to the 1994 pledge request, Bush campaign spokesman Scott McClellan said Friday.

Critics say Bush in 1997 did propose some tax increases to the Texas legislature to help fund a $3 billion property tax rollback.

Bush proposed half-cent hikes in the 6 1/4 percent state sales tax and motor vehicle sales tax; implementing a new business tax that would have extended business levies to sole proprietorships and partnerships for the first time; and spending $1 billion of a budget surplus.

His plan failed, never even receiving a vote.

Instead, legislators approved a $1 billion cut, using the surplus. In 1999, Bush won passage of another tax cut bill — including about $1.35 billion in property tax reductions, $277 million in consumer tax cuts and $229 million in business tax cuts.

"If you go back and look at the history of the tax package, it was a tax cut on day one and it was a tax cut on the day I signed it," Bush said Friday of his 1997 plan.

But in the Forbes ad, the head of Taxpayers for Accountability, Mary C. Williams of Houston, sees it differently, saying: "His record as far as taxes are concerned is a record of broken promises."

That no-tax pledge also sparked controversy during Bush's 1998 re-election campaign. At that time, Bush's chief spokeswoman, Karen Hughes, told the Fort Worth Star-Telegram that the governor didn't sign the document.

"It's a copy of his signature. It is either a tracing or an auto-pen of his signature," Ms. Hughes said then.

But she acknowledged that Bush's campaign returned the pledge to Ms. Williams. She said whoever in the campaign office returned the questionnaire didn't follow Bush's policy of not signing pledges.

Ms. Hughes also told the Star-Telegram that a separate letter that accompanied the pledge — saying almost the same thing and bearing Bush's signature — wasn't signed by him, either, although he authorized its content.

In a phone interview from Houston on Friday, Ms. Williams said Bush — then making his first run for governor — was asked to sign a blanket no-tax pledge issued by her taxpayers' group. Instead, she says, Bush returned to her a modified written statement, which is posted on the group's Internet site.

"I accepted it but didn't like it. You can read it and judge it for yourself," she said. "He's trying to claim he didn't sign the pledge, but he did."

Setting the pledge controvery aside, critics say many Texas taxpayers never saw extra cash because the property tax cuts were eaten up by rising property values and higher local school tax rates. Bush has said a provision raising the homestead exemption from $5,000 to $15,000 was genuine relief, particularly for owners of moderately priced homes.

Mike Hailey, spokesman for the Texas Democratic Party, said Bush not only broke his 1994 no-tax pledge, but the Republican's tax-cutting ideas ignored the state's huge number of renters.

"He proposed a tax increase for half the people of Texas," Hailey said. "The people who rent wouldn't have received a dime's worth of tax breaks, yet Governor Bush proposed they pay a higher sales tax, a higher motor vehicle sales tax and a new business tax that would have caused prices to go up for products and services."