The Europeans are winding up to throw another, bigger monkey wrench into the works of the "Camp David Framework" for settling the Arab-Israeli conflict.

Of course, that's not how they would put it. As with last summer's "fact-finding" tour of the Mideast by Luxembourg's foreign minister, Gaston Thorn, the Europeans will insist they are only trying to fill a dangerous vacuum with their latest "initiative." But "monkey wrench" would be the inescapable effect on Camp David of a new "peace plan" that was secretly agreed to in considerable detail by the nine (now 10, with the inclusion of Greece) members of the European Econonmic Community last December.

The plan goes well beyond fact-finding: it's a blueprint for a whole new framework. No point was seen in pushing it publicly while the United States was changing presidents. But now, with the new, untested Reagan administration in charge, a heavy campaign is about to get under way.

British Prime Minister Margaret Thatcher and her foreign minister, Lord Carrington, are said to be ready to make a big pitch when they came to Washington toward the end of February. France is another loud advocate of anything-but-Camp-David, and French Foreign Minister Jean Francois-Poncet, who is due in town about the same time, will doubtless add his voice.

There are also reports that Foreign Minister Herman J. duMarchie Sarvass of the Netherlands, who has replaced Luxemberg's Thorn as EEC chairman, is angling for an invitiation to Washington to help break the ground for Thatcher -- and planning a tub-thumping tour of the Middle East as well.

The Europeans will argue that they mean Camp David no harm but that it's going nowhere and that their formula offers a promising alternative. Yet the plan they have come up with, as it has been described to by diplomats in a position to know, is far removed from anything that any foreseeable Israeli government could conceivably accept. So much so, in fact, that you have to wonder whether the Europeans are not a let less interested in settling the Palestine question than they are in ingratiating themselves with Arab producers of petroleum and Arab customers of European industries.

Consider the principal features of the European master plan for Arab-Israeli peace.

Item: Israel would be reqired to withdraw from all the territory it has occupied since the 1967 war, including not only the West Bank and Gaza but the Golan Heights and East Jerusalem, over a two-year "transitional period." This goes far beyond requirements of the carefully ambiguous language of the basic "peace" document, U.N. Resolution 242.

Item: With only a few exceptions, all Jewish settlements implanted on occupied territory since 1967 would have to be removed.

Item: In the course of the "transition" period, a referendum would somehow be conducted of all of the estimated four million former inhabitants of Palestine -- worldwide. They would be asked to choose between creation of an independent Palestinian state, or a federation arrangement with Jordon and/of Israel.

Item: As a matter of principle, Palestinian refugees would have the right to return to their original homeland, including what is now Israel, or receive appropriate compensation.

Item: Armed forces, both those of Israel and its Arab neighbors, would be reduced and a U.N. peace-keeping force would be established -- with the Europeans participating.

Item: The city of Jerusalem would either be completely internationalized or divided between Israel and Jordan, with international status accorded to the old city.

You will instantly recognize that these terms (which would include direct dealings with the PLO) violate just about every tenet of Israeli policy. Prime Minister Menachem Begin takes fierce pride of authorship of the much more modest "autonomy" plan. It would gradually grant a measure of self-rule to the West Bank and Gaza over a five-year period, with just about everything else held up for further negotiation. Even Begin's heavily favored opponent in this year's elections, Labor Party leader Simon Peres, has accepted this Camp David "autonomy" approach.

More to the point, so has the Reagan administration.

So why are the Europeans pushing what looks like an obvious non-starter? Not only Israeli officials but some American authorities, as well, see it largely in terms of transatlantic power politics -- a bid for European influence in the Middle East at the expense of the United States. "A reduced American role in the peace-making means less American influence across the board -- and greater economic, commerical and political opportunity for Europe," says one knowledgeable diplomat.

True or not, if Thatcher and other European leaders play out their new initiative, it will put the Reagan administration's foreign policy makers to an early one, and would suppose, unwanted test. Sworn to sweeten Alliance relations, they will be caught between that worthy aim and their equally firm devotion to the security interests of Israel.