In a case brought by lesbian couple Teresa Pires and Helena Paixão, the court said that although the Portuguese Constitution specifically bans discrimination based on sexual orientation, it does not mandate that same-sex marriage be permitted.

”The issue posed to the Court is not whether the Constitution allows the establishment of a system of marriage between persons of the same sex, but is precisely to know if it is imposed in the Constitution,” the court said.

Correspondent João Paulo from PortugalGay.pt said Pires and Paixão ”questioned how can gays and lesbians not be discriminated (against) if they are not recognized the right to marry.” He said the couple told him they will appeal to the European Court of Human Rights.

Meanwhile, the ruling Socialist Party has said it will move legislatively to legalize same-sex marriage, should it remain in power after September’s elections.

Portugal has had a ”de facto unions” law for same-sex couples since 2001 that grants limited rights to all gay couples who have lived together for two years or longer.

Same-sex marriage is legal in Belgium, Canada, the Netherlands, Norway, South Africa, Sweden, Spain and the U.S. states of Connecticut, Iowa and Massachusetts. It also has been legalized in the states of Maine, New Hampshire and Vermont, though the laws have not yet come into effect.