PARIS, Jan 27 (Reuters) - Tens of thousands of people marched through Paris on Sunday to support the French government's plan to legalise gay marriage and adoption, but the turnout fell well short of a mass demonstration against the project two weeks ago.
Police estimated total attendance at about 125,000, while organisers put the number at 400,000. Two weeks ago, organisers of the anti-gay marriage protest claimed turnout of one million, while police put the number at 340,000, an unusually high turnout even in protest-prone France.
"There is a big difference between today's march and the one two weeks ago, which is that this demonstration is one of brotherhood, not of hatred," Paris mayor Bertrand Delanoe, who is openly gay, said on French television.
"The majority of French people wants all couples to have equality in love and parenthood," Delanoe added.
On Tuesday, French parliament starts a two-week debate about the planned law change, which would be one of the biggest social reforms since abolition of the death penalty in 1981.
The government's socialist and green majority is determined to pass the legislation, against which the conservative opposition has lodged some 5,000 amendments.
On Saturday, an Ifop poll showed the proportion of French supporting legalisation of same-sex marriage has risen to 63 percent from 60 percent in early January and December, despite weeks of protest against the planned reform.
Support for adoption rights for gay couples also rose by 3 percentage points, although the country remains divided on the issue, with 49 percent in favour, according to the firm.
Several government ministers took part in the march and will be among a string of celebrities at a party organised by Pierre Berge, partner of late fashion designer Yves Saint Laurent.
Former French Health Minister Roselyne Bachelot was one of the few conservative politicians to support the marchers.
"Nobody has anything to fear from this step forward," she told BFM television.
Henri Guaino, a former top adviser to President Nicolas Sarkozy, told BFM the proposed law was a "a denial of nature" and called for a referendum on the issue.
"It is a negation of the difference between the sexes," he said.
Opponents of gay marriage and adoption, including most faith leaders in France, have argued that the reform would create psychological and social problems for children.
Same-sex weddings are legal in 11 countries including Belgium, Portugal, the Netherlands, Spain, Sweden, Norway and South Africa, as well as nine U.S. states and Washington D.C.
(Reporting by Geert De Clercq; Editing by Jason Webb)