Women who say they have been injured by vaginal mesh implants used to treat pelvic floor problems will claim hundreds of thousands of dollars in damages from makers Johnson and Johnson, the Federal Court in Sydney has heard.

Key points: Class action begins against mesh manufacturer

Class action begins against mesh manufacturer Women say they've been left with "painful and life-altering complications"

Women say they've been left with "painful and life-altering complications" Johnson and Johnson says use of mesh is supported by research

A class action involving more than 700 women has begun, with legal representatives for the women claiming the pharmaceutical giant did not investigate proper clinical trials on the possible complications of the mesh.

If the case is successful, it could lead to payouts totalling hundreds of millions of dollars to affected women.

Barrister Tony Bannon SC said there was a "tidal wave" of aggressive marketing to surgeons and patients that suggested implanting the mesh was a "quick and easy operation".

He told the court the "suffering of the applicants would demonstrate [the] true risks of the … mesh".

"These are risks none of the applicants would have run if they had been properly advised," he said.

Mr Bannon said each applicant continued to suffer significant, unbearable pain.

He quoted an internal email from French doctor Bernard Jacquetin, running a clinical trial for the manufacturer, who allegedly wrote: "I wouldn't like my wife to undergo this procedure."

I've been praying this would come to light: claimant

Outside court, two of the lead claimants in the case said it was a momentous day.

Gai Thompson said she had been waiting for this moment.

"I've literally been praying for nine years that this would come to light, that there would be accountability for what has happened to us," she said.

"No amount of compensation, money, can ever replace what we've lost with our lives with our families, our health, our emotional health.

Gai Thompson (left) with lawyer Rebecca Jancauskas and Joanne Boon (right) are part of a class action against Johnson and Johnson. ( ABC News: Alison Branley )

"For so many years we've been told there's nothing wrong with us, that symptoms are either in our head or it's not because of the mesh.

"I don't think people understand [there's not] one day from the time it's been put in that we haven't had pain — not one day."

The women, including another claimant Joanne Boone, want the mesh banned.

"I had my mesh removed overseas so I've been through a lot of trauma and recovery that has just been, probably even harder since I've had the mesh removed," she said.

"I want to see it banned. It can't go on. There's too many women that are injured."

Many products are still approved for use and available for surgeons to implant.

The mesh is used to treat common complications after childbirth, such as prolapse and incontinence.

Women in the case said it had left them with further complications ranging from severe pain to inability to have intercourse.

Surgeons maintain the products have been clinically tested and have helped many women.

Company rejects claims

Johnson and Johnson has sold more than 100,000 mesh and tape implants but said that did not equate to the number of women affected.

In its submission to a federal Senate inquiry, the company said the use of implantable mesh was supported by clinical research and was often the preferred option to treat pelvic conditions, including incontinence and pelvic organ prolapse.

It was "not able to detail the total number of women that have had transvaginal mesh implants, the number who have experienced adverse side-effects nor the number who have made attempts to have transvaginal mesh removed [in Australia or elsewhere]".