The Reagan administration has mounted a major effort to persuade Congress to end a 14-year moratorium on production of chemical weapons when it begins considering a $188 billion military procurement bill today.

Defense Secretary Caspar W. Weinberger telephoned more than a dozen members of Congress yesterday to restate his conviction that production of nerve gas weapons is "essential" to match similar Soviet efforts.

President Reagan, who called chemical weapons production "a critical defense program" in a recent letter to Rep. Ed Bethune (R-Ark.), also has contacted congressmen.

The first year of Reagan's proposed $6 billion, five-year chemical warfare program is likely to be the most controversial element in this week's debate on his record defense authorization bill. The measure also includes funds for the MX missile, but Democrats are likely to postpone debate on that until after July 4 to allow MX opponents time to regroup, sources said yesterday.

As a result, debate is likely to center on chemical weapons production, possibility of derailing development of satellite-killing weapons and slowing procurement of the controversial B1 bomber.

The bulk of the procurement bill, which accounts for about 70 percent of the administration's proposed defense expenditure of $280 billion, is not in danger, congressmen said.

"These basically are nibbling at the fringes," said Rep. George E. Brown Jr. (D-Calif.), who is leading the fight against anti-satellite weapons. "We're not talking big dollars; we're talking symbolism for the most part."

Bethune and Rep. Clement J. Zablocki (D-Wis.), who led a successful fight in the House last year against funds for chemical weapons production, will offer a similar amendment this year. Bethune said that the United States has stockpiled enough chemical weapons and that administration officials should not cede "the moral high ground" in world opinion by joining the Soviets in making more.

"They the administration made a strong pitch for it last year, and we bloodied their nose," said Bethune, who described his district as "downwind of" the arsenal at Pine Bluff where the nerve gas weapons would be produced. "The inertia of their desire to start a program is what's carrying this. They simply can't control themselves, and . . . they're throwing away an important distinction we have in the world."

Bethune, who said he urged the administration to compromise on the subject during a May 25 meeting with Reagan, Weinberger and Vice President Bush, said the United States possesses more than 7,000 tons of chemical weapons certified by the Army as serviceable. Weinberger, in his annual report to Congress, said those older weapons have "little or no military utility on the modern battlefield."

The Pentagon has argued that its current stock of such weapons is so old that it may have lost its effectiveness.

"Our goal is to eliminate the threat of this particularly abhorrent form of warfare by obtaining a complete and verifiable ban on chemical weapons," Weinberger said. "However, while seeking a verifiable ban, we must be in a position to deter the use of chemical warfare against us or our allies."

Much of the proposed budget would buy protective clothing, sensors and training for soldiers who might be exposed. But $158 million originally was requested to produced binary chemical weapons, in which two relatively safe chemicals would be joined in a lethal compound just before firing.

The administration has withdrawn its request for $43 million for the chemical Bigeye bomb, acknowledging that early tests showed it might explode prematurely. A request to produce 155-mm artillery shells is pending.