Hungary’s new constitution, which bans gay marriage and does not explicitly protect gay people from discrimination, has come into force amid public unrest.

The constitution was enacted 262-44 in April of last year, with 80 members of parliament boycotting the drafting and voting process, and took effect on 1 January 2012.

The document specifically restricts marriage to straight couples and appears to ban abortion by saying that foetuses will be protected from conception onwards.

It does not protect citizens from discrimination on the grounds of age or sexual orientation, and Amnesty International said last year it would not satisfy international human rights laws.

Viktor Orban, leader of the ruling Fidesz party, which came to power with two-thirds majority in the parliament last year, has been dubbed “Viktator” for his leadership style by the crowds who are now protesting the constitution in Budapest.

Tens of thousands have taken to the streets of the capital to voice their opposition to the new state framework.

The former constitution dated back to 1949, with major amendments following the fall of Communism in 1989, and Fidesz argued a new set of rules was vital to deliver the economic growth it had promised Hungary.

But the new text has reportedly removed the safeguards the 1989 amendments put in place, causing wider civil unrest.

US Secretary of State Hillary Clinton had last year urged Orban to enshrine “the independence of the judiciary, a free press, and governmental transparency” in the text.

In a Times piece entitled ‘Back to Autocracy?’, highlighted the discrimation against gay couples in Hungary, saying the constitution “is an extraordinary affront to basic liberties.”

It added that since bans on marriage equality were included in the constitution “no move towards legalised abortion or same-sex marriage is likely to muster the two-thirds parliamentary majority needed to overturn the provisions”.

But Gergely Gulyas, a Fidesz MP, told Reuters when the constitution came into force: “Despite political debates we think it is an important value that for the first time, a freely elected parliament created the Basic Law.”

Lawmakers said the constitution was based on the EU Charter of Fundamental Rights, but gay rights activists have questioned why it does not mention discrimination protections for LGBT people, when gender and race are protected.

The Hungarian organisation of the Helsinki Committee for Human Rights said last year the constitution “expresses a preference for an explicitly defined family model, a certain way of life and conveys the message that it does not wish to become the constitution of those who wish to pursue a different way of life”.

Hungary decriminalised gay sexual acts in 1961 and allows gay couples to register their partnerships but does not allow them to adopt. Since 2002 it has had an equal age of consent and gay people may serve in the military.