Thousands of French lesbians couples are believed to have travelled to Belgium in order to conceive babies, through artificial insemination, which is not available in their home country.

Around 2,000 babies conceived in Belgium through artificial insemination are believe to be born each year to French lesbian couples, who are not eligible for the procedure in France, Reports the Lebanese Daily Star.

Professor Michel Dubois at the University Hospital of Liege, said: “We have seen a sharp increase in demand over the past three years. The word is getting around in France, our patients are passing the message along.”

In early November, French President Francois Hollande’s government approved a bill to legalise equal marriage and allow gay couples to adopt.

The ruling French Socialist government were recently reported to have dropped medially assisted reproduction for lesbian couples, from the country’s upcoming bill to legalise marriage equality.

Belgium allowed gay civil marriage in 2003, and allows artificial insemination for all “regardless of civil status or sexual orientation”.

The babies conceived in Belgium were nicknamed “Thalys babies”, after the high-speed train service between Brussels and Paris, which many of the mothers use to travel back and forth.

For Marie, also mother to a baby conceived in Belgium, “it was galling to have to spend so much money when [French] heterosexual couples get the cost reimbursed.”

“It would be much less hypocritical if women could get this service in France because the politicians know very well that we go to Belgium or Spain for it,” she said.

There are eighteen centres across Belgium offering artificial insemination, and which cater to an overwhelming majority of French women.

For a simple insemination the cost ranges from €350-500 (£290-415).

“French mothers accounted for 80 percent of the 833 artificial insemination cases we handled last year,” said Dubois.

At the largest hospital in Brussels, the Erasmus University Hospital, they only allow two days a year to take bookings for consultations because demand is so high.

“In just an hour and a half, all the appointments available for the next six months are taken. That causes a lot of frustration but there is nothing we can do about it,” said Anne Delbaere of the hospital’s fertility clinic.

She continued that she could not understand the apparent reluctance in France to legalise assisted reproduction for lesbian couples. She said:“It seems to me that they just do not want to accept a reality which has been there for a long time now… These children, these families are there now, whether one likes it or not. Why continue to deny it?”

There are still some limitations to the access to fertility treatment. Some fertility centres have links to the Catholic Church, which is stronly opposed to the French government’s plans.

An anti-equal marriage movement in France, which has organised a rally this weekend hoping to bring out 200,000 demonstrators, has found a leader in a comedian who has denied accusations of homophobia.