In a rare public forecast, Paul A. Volcker, a former Fed chairman and now an economic adviser to President Obama, added his voice to the optimism, although cautiously. “I’m not here to tell you the economy is going to recover very strongly in the short run,” Mr. Volcker said in an interview recorded for a weekend show on Bloomberg Television. But he said the improvement was sufficient to avoid a second government stimulus on top of the $787 billion in spending and tax breaks enacted in February.

An obstacle to easier credit, however, might come from the Treasury Department, which said in a report issued Wednesday that it would step up the issuing of 30-year bonds. The funding is needed to help finance the hundreds of billions of dollars that the government is spending on bank bailouts and stimulus. But the quickening pace could force Treasury to raise long-term interest rates to attract enough buyers for the bonds  an action that in turn could impede lending.

A special advisory committee to the Treasury warned in a report that the government’s huge and rapidly escalating need to borrow money would weigh heavily on the financial markets and that investors would demand higher interest rates in exchange for buying up the avalanche of new bonds.

Until now, that has not been a problem, the report said. Investors have snapped up Treasury bonds as a haven for their money in a troubled world economy, and China invested the proceeds of a huge trade surplus in United States government securities.

“Treasuries will probably not receive the same favorable demand treatment from either source over the coming quarters,” the advisory committee’s report said.

Consumer spending stood out as the only significant bright spot in the Commerce Department’s otherwise bleak update on the gross domestic product, the broadest measure of the nation’s economic activity, which has now posted three straight quarters of decline. Consumer spending turned up in the first quarter, rising at a 2.2 percent annual rate, for the first time since last summer.

Most of the spending was on autos, kitchen appliances, computers and other durable goods. But retailers allowed shoppers to draw down inventories, without reordering to fill their shelves. Indeed, imports, a source of much of the nation’s consumption, fell sharply, along with exports. And so did business investment.