Critics of the Trident submarine say they are finding fresh ammunition in recent actions by the House Armed Services Committee and by the Navy.

The House committee, in reviewing the Pentagon's request for extra money for this fiscal year, refused to go along with the Navy's plea for $20 million to speed development of the Trident II missile.

The Trident II missile has been expressly designed for the giant Trident submarines under construction at the Electric Boat Division yard in Groton, Conn.

"If they're not going to give us the Trident II missile," said a Navy leader, "then we don't need the Trident submarine. We can get by with something smaller and cheaper."

For a Navy officer to express such a view of the Trident submarine, the latest pet project of Adm. H.G. Rickover, is considered heresy by most submariners. But the Trident - at $1.5 billion a copy, almost as much as a nuclear-powered aircraft carrier - is draining of so much shipbuilding money that some Navy leaders are, for the first time, daring to suggest alternatives.

White House budget officials, despite President Carte's recent glowing endorsement of large submarines like the Trident, also fear that the giant submarine - which is 560 feet long, five feet longer than the Washington Monument is high - will price the Navy out of a new surface fleet.

Although the first Trident is already in the water at Groton for final construction, the Trident II missile destined to fill its 24 missile tubes is still on paper. Trident II is intended to be accurate and powerful enough to blow up Soviet missile silos, giving the weapon "first strike" potential.

To fill the gap until 1980, when the first Trident submarine is expected to go into service, the Navy plans to put the Trident I missile inside the older and cheaper Poseidon submarines, thus intensifying their nuclear punch.

If Congress or the White House should decide that the Trident I missile is good enough, the Trident II missile will die aborning. The house Armed Services Committee, traditionally a staunch backer of Pentagon projects, expressed grave doubts about plans for Trident II.

"The Navy has yet to define a firm requirment for a Trident II missile," the committee said in its report on the Pentagon's request for a supplemental appropriation for fiscal year 1979.

"Further, the total program cost for the Trident II is estimated at nearly $8 billion. This represents an affordability problem that the Navy has not been able to adequately address. The committee does not believe it is prudent to initiate this program at present. . . ."

Aside from cost, some critics of the silo-busting Trident II contend it would change the character of the missile submarines from an unprovocative retaliatory force to one the Soviets would have to fear as "first strike." A counter argument is that with land missiles becoming increasingly vulnerable to more accurate Soviet missiles, some of the U.S. silo-busting force must be moved to sea.

Historically, both liberals and conservatives have supported missile submarines in the belief that they provided the United States with an invulnerable unprovocative nuclear deterrent. The Polaris and Poseidon submarine programs are regarded as a highly successful melding of political and military objective.

But the Trident submarine and its Trident @iii missile are under mild challenge - a first for the undersea deterrent. The Navy aided the challengers last Thursday by sending to key congressional committees its secret study of alternatives to giant submarines like the Trident. The Senate Armed Services Committee had asked for the study, so the Navy had no choice.)

The six volumes are a rather generalized presentation, with no firm recommendations for changing course, according to Navy officials. Even so, they supply critics with the biggest pile of ammunition ever for in-depth questioning of national policy for the sea-based nuclear deterrent.