In an atmosphere strikingly remote from the days of military dictatorship less than four years in the past, Greece has plunged into the final days of an electoral campaign with the self-assurance of a mature democracy.

With a flood of fiery last minute speeches, Sunday's parliamentary elections appear to be shaping into a referendum on Premier Constantine Karamanlis' stewardship since the fall of the 1974 military junta.

Unlike the 1974 fall elections, however, when Greeks gave Karamanlis a whopping 55 per cent of the total vote, the forthcoming balloting is taking place with only blurred memories of the seven years of military dictatorship.

Thus, Sunday was expected to provide a more dispassionate indication of shifts in traditional political alignments.

While Karamanlis was not expected to be outpolled by any of his rivals, the test of relative strength of Karamanlis' pro-Western government and leftist parties that advocate drastic changes in Greece's foreign and domestic policies could well serve as a barometer for the course of Greek politics for the coming decade.

Perhaps the most interesting aspect of the vote, apart from the performance of Karamanlis' New Democracy Party, is the popular appeal of the radical Socialist leader Andreas Papandreau, who is advocating a non-aligned foreign policy for Greece.

"Three years ago," Papandreou told an election crowd this week, "Karamanlis got the votes because [immediately after the fall of the junta] his slogan was 'Karamanlis or the tanks.' We put up with his proud bearing once, but we will not do it twice. Vote however you want in these elections. But don't vote out of fear."

It is unlikely that Karamanlis, one of the last remaining European leaders who rose to national prominence during the post-war years, will match his 1974 election total. Even with all the charges and countercharges of his political opponents, however, the 70-year-old prime minister is expected to collect the 42 per cent necessary to form a majority government under the country's highly complicated electoral law.

This aspect of the voting, then, comes down to leaders of the opposition for Parliament's No. 2 spot. The main contenders are incumbent George Mavros and his Center Democratic Unioin and Papandreou's Panhellenic Socialist Movement.

An uneasy coalition of old-style liberals, conservatives and social democrats, the Democratic Union is believed to have lost ground since the 1974 elections, when it captured 20.4 per cent of the vote. In a campaign where there are remarkably few substantive issues, its program, particularly its emphaisis on Greek entry into the European Economic Community, does not differ substantially from that of Karamanlis.

Despite Mavros' verbal barbs at the prime minister accusing him of running a "do nothing" government and creating a "one-party state," there are recurrent reports that the two might form a coalition government.

The lines are thus drawn between this potential coalition and the three major parties of the left.

The 58-year-old Papandreou, a fire-brand socialist who once headed the economics department at the University of California at Berkley, is odds-on favorite to become chief of the parliamentary opposition. Experts caution, however, that his huge rallies and rapt supporters do not necessarily translate into votes.

Traditionally conservative, the 4.5 million voters outside key urban centers could, in the view of political analysts, prove to be key swing districts in the parliamentary race.

There are also a half-million young first voters and the imponderables of a televised campaign, which has brought all major speeches and rallies into home across the country for the first time.

Elias Eliuo, the widely respected old-man of Greek communism, heads the new Alliance of Progressive and Leftist Forces, linking Eurocommunists. Socialists, and Christian Democrats. He says that the alliance will be the surprise of the election.

Rounding out the five major parties is the Orthodox Greek Communist Party, which is standing under its own banner for the first time in 41 years. The party is closely aligned with Moscow and reportedly receives $2 million from the Kremlin each month.

The parties of the left have essentially similar foreign policy planks - a withdrawal from NATO, the abolition of American bases in Greece, no concessions to Turkey on Cyprus or the Aegean Sea, and varying degrees of objection to entering the Common Market. If they reach their maximum electoral targets - totaling about 35 per cent of the vote respectively - they could present a formidable parliamentary opposition to any new Karamanlis government.

The prime minister is standing on his record, emphasizing the stability he has given the country and its role in Europe and the West. With only one speech left before the election, however, he has conspicuously avoided the potentially inlammatory issues of Greece's role in NATO and relations with the United States.

Of all opposition parties, however, Karamanlis has reserved his verbal fusillades for Papandeau.

Charging that Papandreau's program is unrealistic by promising all a "brave new world," Karamanlis likened his socialist foe to "Christopher Colombus, who left without knowing where he was going, and when he arrived he did not know where he was."

Reinforcing his reputation as a superb politician, Karamanlis appears to have preempted the main threat to his own party - meaningful challenge from the right. The hastily assembled National Rally, led by Stephanos Stephanapoulos, a 77-year-old former premier, could have been the spoiler of the election if it has been able to corral the full spectrum of the disgruntled conservatives, but the party has both angered and frightened many conservatives by the increasing violence of its electoral campaign and by its overt ties with the former military dictatorship. It has called for an amnesty for junta leaders, who are imprisoned for life.

Above the din of the loudspeakers, the 2,100 candidates competing for Parliament's 300 seats, and a campaign that cost $7 million, Greek politics continue to be based more on personalities and patrons than on issues or ideology.