The White House is counting on continuing voter concern about inflation to cool the Senate's tax-cut fever during the current congressional recess and to persuade the lawmakers to put off any tax-cut legislation until next January.

Administration officials asserted in interviews they are convinced the lawmakers will find most voters still fearful that enacting a tax bill now would refuel inflation, and that Senate Democrats overlooked this in pledging one by Sept. 3.

They also confirmed that, barring congressional opposition, the administration would like to postpone the effective date of any tax cuts for individuals until next June or July from Jan. 1 as the lawmakers want.

Carter administration officials are worried that too early an effective date would bloat the fiscal 1981 deficit more than necessary and might unsettle the financial markets and send interest rates soaring again.

The administration's assessment of the voters' mood is being reflected in a new counterattack against the tax-cut push launched by President Carter's speech yesterday sharply criticizing Ronald Reagan's new tax-cut plan.

The feeling among top Carter political and economic advisers is that Senate Democrats simply overreacted in promising to report out a tax-cut bill by Labor Day, misjudging voters' likely reception of the Reagan proposal.

White House aides point out that Reagan's basic proposal -- for a sizable across-the-board cut in individual tax rates -- was defeated in the 1978 elections.

Adminstration strategists cite recent surveys by private pollsters that they say show a majority of Americans opposing a tax cut for the first time in recent memory.

"People know there's no free lunch out there," one adviser said.

What the White House hopes will happen is that recess-bound lawmakers will discover that voter enthusiasm for a tax cut is weak enough to cool their tax-cut fever and, hopefully, postpone passage of any legislation until 1981.

Sources noted that before the Reagan plan was proffered two weeks ago, there was little visible sentiment in Congress for taking up a tax-cut bill this session. Lawmakers asserted the voters wanted the budget balanced instead.

What White House strategists hope is that the Senate will back away enough to allow the House Ways and Means Committee to delay any action until early in the 97th Congress.

Ways and Means Chairman Al Ullman (D-Ore.) opposes taking up a tax-cut bill this year, but has agreed to schedule hearings July 22 to avoid losing the initiative to the Senate Finance Committee.

Congressional sources, disclosed that Democrats on the Ways and Means panel indicated in a private caucus Wednesday that they still are unenthusiastic about considering a tax-cut bill this year.

However, observers said the panel is expected to report out a tax-cut bill this year if push comes to shove, if only to underscore the House's constitutional prerogative in originating tax legislation in Congress.

"The House still could go either way," said one key Carter adviser, reviewing the situation yesterday.