WASHINGTON – Congressional leaders have promised President Obama they will come up with a comprehensive healthcare reform bill by Oct. 1. The president says any reform plan needs bipartisan support in order to be sustainable. As congressional panels and party leaders begin their campaigns in earnest, the heat on both sides of the aisle-on and off Capitol Hill-- is starting to mount.

 Wednesday, the Senate Committee on Health, Education, Labor and Pensions, chaired by Edward Kennedy (D-Mass.) spent its first day in markup of his healthcare bill, the Affordable Health Choices Act. Republicans balked at the "high costs" of the bill and "failure to cover tens of millions of Americans."

Markup of the Kennedy bill, touted to reduce costs, protect choices and guarantee quality affordable health for all Americans, is expected  to continue daily through June 26.

According to Sen. Mike Enzi (R-Wyo.), Republicans opposed a markup of the Kennedy bill while key sections of the bill still remain blank and the Congressional Budget Office (CBO) has not been able to provide formal cost estimates of the entire proposal.

"The fundamental flaws in this bill are the direct consequence of how the bill was put together," Enzi said. "The bill was drafted exclusively by Democratic staff, who excluded Republicans from the process of preparing the actual legislation. That is not how Senator Kennedy and I worked together in the past, and this is not how we managed to produce an impressive record of bipartisan accomplishments at this committee."

Enzi said Republicans will likely offer amendments to rein in exploding health care costs, including by reducing the number of medical lawsuits and curbing waste, fraud and abuse,.

 Sen. Chris Dodd (D-Conn.), filling in for the ailing chairman Kennedy,  defended the bill and the hurried pace. "For the health of our economy and the health of our families, health care reform cannot wait, must not wait, and will not wait.  We have to get it done, now. We owe the working families of this country legislation that cuts costs, protects choice, and ensures affordable, high-quality care.  And we intend to deliver."

Meanwhile,  former senators Howard Baker (R-Tenn.), Tom Daschle (D-Iowa) and Bob Dole (R-Kan) issued a reform plan through the Bipartisan Policy Center (BCP) Wednesday  that they claim could garner bipartisan support.

The former senators told CBSNews.com Wednesday that Congress should strive to gain around 20 Republican votes to truly make any reform plan a bipartisan bill.

Senate Finance Committee Chairman Max Baucus (D-Mont.) said Wednesday that the Baker-Daschle-Dole plan has similarities to his own plan, and shows that bipartisan consensus is within reach.

"The proposal not only helps identify areas of clear agreement, it addresses critical reforms, such as tackling cost concerns and ensuring quality coverage while holding insurance companies' feet to the fire," he said.

"The BPC proposal also includes insurance exchanges to make it easier and less expensive for every American to purchase health insurance, and protects the idea of shared responsibility by employers, individuals and government - both of which are critical to comprehensive health reform," Baucus said.

Sen. Chuck Grassley (R-Iowa), ranking member of the Senate Committee on Finance said he does not support every aspect of the BPC plan, but it should encourage Congress that a bipartisan plan may be achievable.

 Also on Wednesday, Health and Human Services Secretary Kathleen Sebelius said at the New Democratic Leadership Council Policy Forum in Washington, D.C., there is "incredible support" for reform, and passage of a bill is months away.

 "Groups that were once sworn enemies continue to sit at the table and work towards a solution," Sebelius said. "Patients and doctors, business and labor, Democrats and Republicans all know that reform cannot wait."

 Other signs off Capitol Hill reflect the mounting tension over healthcare reform. Michael Steele, chairman of the Republican National Committee  issued a plea Thursday to gather support for fair media coverage. Steele and the committee claim ABC News will favor Obama by presenting his healthcare reform plan during a World News broadcast June 24 from the White House, without offering a chance for Republicans to express their point of view. Steele said ABC "flatly rejected" the Republicans' request.

 According to St. Petersburg Times' Politifact.com, a new ad by the liberal group Americans United for Change, urges support for President Obama's push for major health care legislation. The ad argues that 62 percent of the public supports "the president's plan to reform health care," and that Republicans in Congress should too. Politifact's finding show the majority of Americans support health reform, not necessarily Obama's plan.