The telephones have been ringing off the hook at U.S. mortgage lenders since President Barack Obama pledged $275 billion on Wednesday to help stem a wave of home foreclosures.

Yesterday, LendingTree.com had the highest loan request volume day for the month showing that borrowers did indeed feel encouraged by Obama's housing plan, said Cameron Findlay, chief economist for the online loan broker in Charlotte, North Carolina.

In the strongest government action yet to aid homeowners since the housing market's meltdown began, President Obama said his plan would give 9 million families the chance to refinance their mortgages.

Refinancing volume at mortgage broker LendingTree.com was up 88 percent week-over-week on Wednesday, while applications for new home purchases were up 30 percent during this time.

Traffic to real estate website Zillow.com soared as well with loan requests up 56 percent on Wednesday versus the average daily number of loan requests so far in February.

The U.S. housing market is in the worst downturn since the Great Depression, contributing to losses at banks and a global economic slowdown.

Many hopeful borrowers, however, may find their efforts to get a loan futile despite the U.S. government's aggressive efforts.

The government could and should do more and I think they are being overly optimistic about the number of people that are going to be helped by this, said Professor Chris Mayer, senior vice Dean at Columbia Business School.

It will help foreclosures, but the plan falls short in several ways, namely it is missing a provision that provides a safe harbor for servicers to modify mortgages, he said.

Mayer said about 50 percent of mortgage servicers have some sort of restriction on modification in the pooling and servicing agreement, which can only be changed through legislation.

The amount of homeowners helped with the housing plan is significantly less without this provision, he said.

Under Obama's housing plan, up to 5 million homeowners still making payments, who cannot qualify for conventional refinancing because their home values have dropped, could refinance through Fannie Mae and Freddie Mac.

Separately, up to 4 million at risk borrowers in danger of foreclosure could get payments reduced through modifications jointly paid for by lenders and the U.S. Treasury. Those reductions would aim to bring borrowers payments down to 31 percent of their income.

Mortgage finance giants, Fannie Mae and Freddie Mac, will play a pivotal role in the U.S. government's housing plan.

The involvement of Fannie Mae and Freddie Mac in this process is significant and the impact should not be underestimated, said Susan Wachter, real estate and finance professor at the Wharton School, University of Pennsylvania.

The housing plan, however, only offers incentives, with no penalties and that could be a problem, she said.

The plan would provide a $1,000 fee to mortgage servicers for each successful loan modification, while borrowers would receive up to $1,000 to reduce their loan principal each year if they stay current on their payments.

There has been a stunning absence of evidence that past plans to modify loans have worked, but if we do eventually get evidence that these new loan modifications are working that in and of itself will help the housing market, she said.

Stabilization of the mortgage and housing markets remains a prerequisite for a turn toward normalization of financial markets and the economy, according to Torsten Slok, senior economist at Deutsche Bank in New York.

The policy measures taken have already had a significantly positive effect on housing affordability, and they show promise of helping further to ease the downturn in housing ahead, he said.

But, they will not be enough to prevent substantial further declines in either residential investment or home prices over the quarters ahead, he said.

(Additional Reporting by Caren Bohan and Jeff Mason)