The French parliament has begun its second week of a marathon gay marriage debate, with bickering MPs verbally attacking each other day and night, highlighting problems François Hollande faces in his attempts to push through his flagship social reform: the legalisation of gay marriage and adoption.

In a seven-day slanging match, which has made the Westminster debate look tame, the French right has attempted to draw out the proceedings for as long as possible. More than 5,300 amendments have been tabled by the opposition, some of which were absurdist, such as the demand that polygamous and incestuous marriages be legalised in the name of equal rights.

Several rightwing MPs warned of an influx of gay foreigners wanting to marry in France. With about 3,000 amendments still to be dealt with in at least another week of debate, the spats are continuing, with the speaker of parliament often urging both sides to calm down.

During the weekend sitting, the first time in more than eight years that the parliament has sat through Saturday and Sunday, including at night, the left and right sparred over who had been more offensive by making references to the Nazis' treatment of gay people. MPs argued about whether "clown" was an appropriate insult and variously accused each other of being "mute carps" and "dictators".

With the majority Socialists avoiding talking for long in order to speed up the proceedings, many tweeted from the benches to vent their ire.

This in turn infuriated the right. One session was adjourned to restore order after one of the rightwing UMP party's key speakers was likened to Bree Van de Kamp from Desperate Housewives in a Green party MP's tweet.

Le Monde marvelled that from Friday to Sunday the transcript of the debate amounted to more than 240,000 words, about half the text of Victor Hugo's Les Misérables.

On Saturday, MPs approved the central plank of the new law: that marriage should be an agreement between any two people, not just a man and a woman. But differences remain before the final vote takes place next week.

While 55 to 65% of French people say they are in favour of gay marriage, only about 50% support gay adoption, the second part of the law.

The divisions have been played out on the streets. A demonstration against gay marriage in Paris last month attracted hundreds of thousands of protesters in the largest gathering of Conservative and rightwing protesters in 30 years. A pro-gay marriage rally followed.

The biggest sticking points have been the issues of adoption, parental rights and the right to medically assisted procreation for same-sex couples.

The proposed law does not give automatic joint parenting rights to gay couples who have a child together, nor will it allow medically assisted procreation including IVF. This has infuriated many on the left of the Socialist party and angered rights groups, who argue the law does not go far enough.

A later bill on family issues, which might consider access to medically assisted conception by same-sex couples, has been promised by the end of the year, but many are sceptical about whether it will come to pass.

With the Socialist party holding the majority in the National Assembly and the Senate, the government expects the bill legalising gay marriage and adoption to be passed at the end of April.