Grave charges have surfaced in the British press against Sir Peter Ramsbotham, their ambassador to this capital, comprehends the seriousness of it all.

In a nutshell, the charges boil down to a bill of particulars in which the ambassador is not docketed for breaking any particular law - not any legal law - but is said to have committed awful crimes all the same. Specifically (and here one may summarize the scattered indictments floating about England) he has:

Shown himself unfit by age (he is 57; Carter is 52; and Amy is 9) to establish rapport with a youthful American administration.

He has sung music hall songs in a costume with a false mustache on at least one (1) occasion.

He has gone bird-watching down in Virginia and is therefore a fuddy-duddy, and he has puttered about in the embassy garden as well, and this may be even more fuddy-duddy.

Not only has he projected a fuddy-duddy image, but has also allowed actors and actresses - Telly Savalas and Elizabeth Taylor, for example - inside the embassy itself, which shows a deplorable lack of dignity.

He is a snob. He has invited fashionable persons into the embassy, instead of being on the lookout for Britain's economic advancement in the world.

Apart from being a snob, he has States (Dayton, Spartansburg, Anchorage, Phoenix, Nashville, etc., etc.) talking to just anybody.

Not only has he been too democratic, he has also been entirely too elitist, and once let Henry Ford spend the night, and the chairman of Chrysler is coming next month.

These are matters of legitimate concern, and he is to be succeeded by Peter Jay (aged 40, an economist and a newspaperman) while Ramsbotham is being sent to govern Bermuda where it doesn't make any difference if he's too old, too young, or too in-between.

When Sir Peter began hearing these charges, he declined, for some reason, to take the chair to state he is not now and never has been a fuddy-duddy. On the contrary, he refused to see reporters or to answer their questions as to the present state of his complicity in the alleged crimes aforesaid. He said he was delighted to be followed by a man (Jay) of such brilliance: Period.

Sir Peter is a career diplomat and (some say) does not see the gravity of his predicament or any used to plead innocent.

His friends (even bird-watchers have a few) who read the charges going around in London began to explode. To summarize what various ones told this newspaper, the charges are "a damned outrage," "a stupid libel," "a foolish policizing of the Foreign Service which ought to be kept out of self-serving politics," "a cheap shot" and "hardly what one would have expected of the Brits."

Elizabeth Taylor, informed of the charges that she had not only entered the embassy but also met her husband John Warner (formerly chairman of the Havy) in that place and that this Bicentennial Commission and Secretary figured in the complaint, stated:

""You're kidding."

Sir Peter, she said in an informal deposition by phone to the press, is "dignified, warm, human," and a "superb representative of Britain who has done an absolutely remarkable job of diplomacy in Washington," and - she implied - is not guilty of high crimes.

As for possible ineffectiveness with the young Carter people, some flippant residents of Washington pointed out he is nearer Carter's age than the proposed new ambassador would be.

They also say that Ramsbotham was the first ambassador President Carter asked to the White House, and that Carter conferred with him before taking off for London recently.

Bert Lance, a Carter insider who directs the Office of Management and Budget, had no intention of getting in the middle of a British family row about image, but did say he he had found Sir Peter and his wife, Frances, to be "outstanding folks." He said he meant nothing to be taken as opposing Peter Jay, that is not his meaning at all, but he did wish to say of Ramsbotham that "I think very very highly of him, he is a very able man."

A fellow at the State Department, if a man so high can be called fellow, said "Ramsbotham has been effective, well-liked and respected."

In America, nobody is shocked at bird-watching or liking Elizabeth Taylor. Not everybody here thinks James Schlesinger, for example, is a fuddy-duddy though he watches birds even more than Ramsbotham. But in austere England it is different, and there one cannot be too careful of one's reputation.

Not even the English have yet lodged against Ramsbotham the crime of crimes - failure of a sense of humor. Either they have not thought of if, or fear being laughed out of court if they tack it on to the indictment.

The embassy here has clammed up, and no wonder, for never before has a British ambassador's reputation been questioned is so grave an area as suspected fuddy-duddyism. Not publicly.

It is known, of course, that Ramsbotham has five working lunches or suppers a week, usually for five or six people. Sometimes there are old Meany folk there wrangling about labor. Sometimes oil folk. Sometimes, God only knows what bizarre types. Even American under secretaries.

In a probably attempt to pretend the charges are groundless, some within the embassy have reminded inquirers of happier days - before last week - when it was common knowledge that Ramsbotham, more than most ambassadors, has called in subordinates and briefed them on his highest level conversations, sought their reactions, and encouraged a flow rare in embassies of constant feedback from consults in minor towns.

"They'd all die for him, of course," said one Washingtonian who knows a lot of embassy people. Not that that proves anything one way or another."

One embassy staffer once faced a crisis involving another person's health and was deep in distress. He told a Washington person, "at least, thank God, I can say anything to him (Sir Peter) and he will understand."

An employee with an unglamorous job once sounded off in a way that might have caused some embarrassment to a lesser embassy. Sir Peter made some phone calls, had a little talk or two, and everybody forgot the matter.

The London prosecution - those who have raised the virtually unanswerable spectre of fud and dud - have not yet learned (this newspaper has reason to believe) of some of Lady Ramsbothams actions here, it is not yet known in London that her embassy cat has stalked about under the tablecloth at embassy meals when guests were present, doubtless giving an incorrect impression to guests who felt their legs being stroked.

"We are fond of the cat," she once went so far as to confess.

On another occasion, at the Egyptian embassy at a great do in honor of the American ambassador to France, she so far forgot her position as to drop an earring and invite the men to please hunt about on the floor for it before it got squashed. The following scene was shocking, as many international rumps - some of them overweight - were noticed for the first time, while the general diplomatic corps pawed the floor for the earring. It is presumed this will be added to the list of alleged Ramsbotham crimes.

A couple of bleeding-hearts (always abundant in Washington) have said it's a crying shame for a man of dignity and honor to conclude his substantial career in this capital under the cloud of vague charges in the British press. The whole thing is a warning, of course, not only to other ambassadors but to all humans who have knocked themselves out for some job or other: Bert Lance may say you're okay, but can you prove you're not a fuddy-duddy? If so, start testifying.

Some Americans can say - it's easy for them, they're not on trial - that a weak government in London under attack in England for naming a prime minister's son-in-law to a top job, has tried to becloud things by inventing an ineffective "image" for Sir Peter.

"If a man is intelligent," said one partisan, American friend, "and you can't think of anything else against him, you can hint he is a fuddy-dutty. How do you prove you aren't? They got you."

"Wheels turn," Sir Peter wrote a friend last week after the charges surfaced, and let it go at that.

Commerce Department figures for the past year show American investment in British industry was about $4.5 billion, a substantial rise from the past, and of this a lot was investment in the North Sea oil project. Counting that, Britain accounted for 37 per cent of American investment in Europe. Not counting oil, but just manufacturing, Britain accounted for 27 per cent of American investment in Europe.

A lot of hardnose American investors have been suspicious of a socialist British government that seems to keep having labor and financial troubles. One of Ramsbotham's most energetic programs has been to ask Americans with investments in British industry what their problems are and how he could help.

Among some American businessmen in Dayton, Dallas and so on, expressions of ambassadorial concern for their problems has probably not done any great damage.

A lot of those people do not sparkle and rarely make the American gossip columns - few fawn on them is Washington, actually - but their companies are important to Britain, and investment figures suggest that Ramsbotham has not done any harm, since more dollars flow to British investments than to German or French.

However bizarre it may seem in high-minded London, a lot of Americans like Elizabeth Taylor and Telly Savalas are not all that shocked that they got in the door of the embassy of England itself. The Ramsbothams are pretty friendly.

It's no answer to the charges, of course, but most people seem to think Ramsbotham's greatest gift is his warmth. People open up and feel safe in his house, a sentimental wag once said.

Nobody denies that Ramsbotham has made 30 tours (mostly for five days each) to places in America outside the East Coast, is it is commonly conceded that he somehow established some sort of rapport with Carter people even before they won the election.

But he's an awful lot older than Amy. Maybe that's a problem. Or maybe it's those damned birds. Sir Peter cannot very well deny he'd walk a mile to see a pileated woodpecker or Hawkamoor's sulfur-toed glauk. He's a birder, granted. Birders are all fuddy-duddy if not worse. It follows, therefore, he must be guilty as charged (millions will say) and that will be that. Wheels turn, and who in a cynical age cares much what is turned from the spokes? That is what his friends will tell you. Some of these are mad.

Ramsbotham is to leave in July to be governor of Bermuda. Then when he retires, back to England. He's a countryman. Dogs, rhododendrons, all that. The sort of man who might well write The Times he has seen the first cuckoo of the year in England. If he looks in the right places, his friends have hinted, he might find more than one in London itself.