The day after U.S. Senator Edward Kennedy's burial, leading Democratic and Republican senators on Sunday seized on his reputation for compromise to call for cooperation in the healthcare debate but showed little give in their own positions.

The Democratic-led Congress returns in September to work on a U.S. healthcare overhaul plan criticized by Republicans as too costly and as promoting government-run healthcare.

Here's what Teddy would do. He'd say: 'I'm going to fight the fight, and if and when we get to the point that we can't get there, we'll see whether or not we can do enough to make good happen out of this. And you can't make that measurement today, Senator John Kerry, a Democrat, said on ABC's This Week With George Stephanopoulos.

Kennedy, who called healthcare reform the cause of his life, died last week of a brain tumor.

As President Barack Obama pushes for a plan that includes a public insurance option to compete with private plans to bring down costs, Kennedy's death leaves Democrats one vote short of the 60-vote supermajority needed to overcome procedural blocks from Republicans.

Some Democrats also are resisting the public option as part of reforming the $2.5 trillion healthcare sector and expanding coverage to some 49 million uninsured, leaving it in peril.

Some of Kennedy's closest friends, Republicans and Democrats, were on the Sunday television talks shows for tributes to him but on healthcare reform agreed on little other than the void he left in the debate.

Republican Senator Orrin Hatch emphasized Kennedy's reputation as a deal-maker willing to make compromises to pass needed legislation.

If (Kennedy) was here, I don't think we'd be in the mess we're in right now, said Hatch, who said he could be willing to rejoin the debate after dropping out of discussions in July.

There are some ways we could do this. Both sides are arguing for insurance reform. That's not the issue. The issue is how do we put these things together, Hatch said on ABC.

But the senators stressed that a compromise would come only after an all-out fight in Congress and made no suggestion that they were willing now to surrender ground.

Kerry said Kennedy would fight for the public option and do everything in his power to get it, but if he didn't see the ability ... to get it done, he would not throw the baby out with the bathwater.