Heads of government of the 10 member states of the European Community yesterday approved compromise proposals on wine production and thereby cleared the way for final negotiations by Spain and Portugal to enter the Community on the target date of Jan. 1, 1986.
The deal was put in jeopardy late Tuesday by last-minute threats by Greek Prime Minister Andreas Papandreou to hold it up. But the other leaders, at the end of their two-day summit meeting in Dublin Castle, persuaded him to withdraw his objections.
The wine compromise was put forward by Garret FitzGerald, the Irish prime minister and current president (under a rotating system) of the European Commission.
It proposed that any curbs on wine production should be decided region by region instead of country by country. The plan is that excess production will be sold off cheaply and distilled into industrial alcohol. This plan satisfied the Italians, the biggest wine producers.
Agreement on Spanish and Portuguese accession was seen as vital because the West German government had threatened, in the absence of an agreement, to block proposals for increasing funding for the Community budget. The breakthrough was regarded as a considerable success for the Irish presidency of the Community, now reaching its end, and for Dr. FitzGerald personally.
Still to come before Spain and Portugal can join the Community are vital negotiations with their governments, centering on the question of fishing rights. The Spanish have a fishing fleet bigger than the combined fleets of all 10 countries in the Community.
Spain is dissatisfied with a previous offer that would involve a delay of 15 years before Spain would have access to all the waters of the member states. The coming negotiations are certain to be tough, but the consensus in Dublin Castle yesterday was that the target date for membership is now realistic.
Enlargement of the Community will make a considerable difference to the geographical and strategic ''profile'' of the European Community. It will increase the land area by 38 percent and the area under cultivation by 34 percent.
Spanish accession alone will increase production of vegetables by 25 percent, fruit by 48 percent, and olive oil by 59 percent.
There is also the considerable strategic importance of the Iberian Peninsula.
Irish troops and police carried out a massive security operation over the last two days, equaled only by the security seen during President Reagan's visit here last summer. Streets around Dublin Castle were closed to all traffic and Army snipers manned nearby rooftops. The authorities were concerned for the security in particular of British Prime Minister Margaret Thatcher, after the recent assassination attempt in Brighton, England, by the Provisional wing of the illegal Irish Republican Army. A demonstration against her presence in Dublin was attended by only 1,500 persons on Monday and passed off peacefully.
Yesterday a British television technician was caught playing a prank by trying to smuggle a bullet through the security net into Dublin Castle. He was taken to court and fined $50.