On one side is Melina Mercouri, the actress who has infused her new career as representative of the people with the same tempestuous spirit she brought to her stage and film roles.

On the other side is the Greek parliament, that patrician citadel of male dominance, bending a bit but still defying the Mercouri storm.

Swept into parliament in November, as a member of the main opposition party, the Panhellenic Socialist Movement, Mercouri, 51, has caught the nation's attention through her battle to wear trousers in the chamber and her indignation that there are no private toilet facilities for women deputies. In her maiden speech, she lashed out at government-controlled television, and admonished her constituents not to pay their electricity bills as a protest against the television ta x.

"Let them cut off my electricity . . . but all this fuss about my trousers is ridiculous," Mercouri said. She has appealed to the speaker of the chamber, Dimitrious Papaspyrou, 78, to amend the dress code which specifies that deputies must be "properly clad."

"I wore trousers because I am a working woman," protested Mercouri, now rehearsing a special program on Bertolt Brecht. "Being there for an important vote was certainly more important than the way that I was dressed."

Revolutionizing the long-time male bastion where sexegenarians dominate, the unprecedented 10 female deputies - and their demands - have brought cries of exasperation from their male collegues.

As a cocession to its female members, parliament had approved a sprinkling of restroom facilites for women, though to reach them one must walk past open urinals for men.

"When I was told there were no private facilites for women," bristled Mercouri, "I told the security official, "You stay right there and guard the door. I have work to do. I can't rush all over Athens looking for a place to go."

The telephone in her chic Kolinaki apartment rings relentlessly with calls from chawomen, unwed mothers, disabled veterans and scores of men. It seems a long way to her constituency in the working class district of Nikaia, Piraeus, though it's only a 40-minute drive.

It was here that she lived among prostitutes and drug pushers to prepare for her internationally acclaimed film, "Never on Sunday." And it was here, despite her upperclass, Athenian orgins that she returned to run for parliament.

Granddaughter of a legendary Athens mayor, daughter of a leftist deputy, the fiery Mercouri is a marxist. Her constituents, in her words, are "among the most neglected in Greece."

"The people of Piraeus trust me," said Mercouri, "and I'll never let them down. Their living conditions are writched . . . Women have no pensions as housewives. They have no day care centers, for all intents and purposes, no right to divorce . . . Only now are they beginning to realize that they have rights as citizens. They are ready to be dynamic, and we've begun to organize. They are ready to be dynamite, and we've begun to organize. They know nothing of Marx and Lenin, but have the practical experience of the drudgery of their lives."

Mercouri works a 16-hour day. She commutes regularly to her storefront headquarters in Nikaia between mottled tenements and the bustling neighborhood square.

"Eighty percent of the problems people bring me," said Mercouri, "have to do with the November floods. The area was devastated, lives ruined . . . 28 people died."

Mercouri has raised $8,000 to aid the victims through benefit performances and private contributions.

"But this isn't the way they should be compensated . . . The whole sewage system has got to be improved . . . there's only one hospital in my district for 150,000 people. The schools are deplorable. We have so much work ahead of us . . . Revolutions are not made with songs."

"I'm so tired," she said in her apartment. "I can't do theater, anymore . . . I've got so much to learn. My place is in parliament.And we'll show them," she continued, the fire returning. "I'll bring 2,000 women to protest in Parliament. Damn it, we'll get our rights."

When Mercouri delivered her maiden speech in Parliament, her constituents were there. They waited patiently until she finally spoke at 1 a.m. Even then, the public gallery was packed.