Democratic governors and congressional leaders told President Reagan yesterday to forget about his plan for turning programs back to the states until he cures the economy and curbs big budget deficits.

After a caucus with some of the Democratic state executives gathering here for the winter meeting of the National Governors Association, starting today, Assistant Senate Democratic Leader Alan Cranston of California said Congress should not be "diverted" from budgetary and economic issues to Reagan's federalism initiative until "deficits are in hand" and unemployment is cut by one-third to 6 percent or less.

He said he did not know when that would be.

Three Democratic governors who joined Cranston and House Rules Committee Chairman Richard Bolling of Missouri at a Capitol press conference were less scornful of the Reagan plan for swapping and turning back programs to the states.

But California Gov. Edmund G. (Jerry) Brown Jr., chairman of the Democratic governors caucus, said that while a "good faith discussion" of the Reagan proposal would be welcomed, "no governor wants to raise taxes in his state to bail out Ronald Reagan's $100 billion deficit."

North Carolina Gov. James B. Hunt, chairman of a key committee for the governors association, said "governors have great concern about the fairness" of the Reagan plan.

"If it's going anywhere, it has to be done at a time when we're not cutting so deeply" into domestic programs, he said.

Kentucky Gov. John Y. Brown said priorities for 1982 had to be "getting unemployment down and getting productivity up."

While other southern and western Democratic governors are expected to be more supportive of the Reagan initiative, the effect of yesterday's statements was to throw cold water on prospects for the Reagan plan.

The president announced his federalism initiative in his State of the Union address last month, outlining a phased-in, seven-year program to begin late in 1983.

Under his plan, there would be a major program swap, with the federal government taking over the state share of Medicaid, while the states take over food stamps and the main welfare program.

Some 40 other domestic programs would be transferred to the states.

Interim financing would be provided by federal excise and oil windfall profits taxes but by 1991, under the Reagan plan, states would have full responsibility for funding any programs they kept operating.

Reagan made it plain from the outset he was ready to negotiate the timing and details of his proposed swap and turnback.

White House aides have worked hard to gain an endorsement of the president's initiative from this meeting of governors, in order to get their help in drafting a formal proposal for Congress in the next six weeks or so.

Presidential assistants said that was still their goal, but yesterday's Democratic caucus put a sharp partisan tinge on what they had hoped to keep a bipartisan discussion.

And, contrary to White House hopes, it tied the federalism plan directly to the raging battle over Reagan's fiscal 1983 budget.

Jerry Brown said Democratic governors "do not want decentralism to become another Trojan horse whereby a disguised tax increase is indirectly created by the transfer of burdens" to the states.

Cranston said the governors had told Congress, "Let's not get into this until we're in better shape and are ready to assume the burdens."