Legislation establishing a buffer zone around Victorian abortion clinics looks certain to pass Parliament today, making it illegal for anti-abortion protesters to harass women outside the clinics.

The bill, originally put forward by Sex Party MP Fiona Patten, but adopted by the Labor Government, will establish a 150-metre safe access zone around all medical clinics that offer abortions.

It follows years of complaints from the clinics about pro-life campaigners approaching women outside clinics, urging them not to terminate their pregnancy.

Footage supplied to the ABC by pro-choice campaigners earlier this year showed that one woman was blocked from leaving her car by a female protester as she pulled up outside the clinic.

As the protester moved on she could be heard saying "Don't kill your baby".

The bill will be debated in the Upper House today and has the support of the Labor Government, the Greens and the Sex Party.

The Coalition is allowing its members a conscience vote on the issue and it is expected a majority will support the bill.

Ms Patten is confident the bill will pass in its current form.

"There will be a lot of debate, there may be some amendments put up, but I expect this bill to go through without amendment," she said.

"Women will finally be free of harassment around abortion clinics."

The new laws are expected to come into force in January.

They will include significant fines for protesters who breach the safe access zone, and potentially jail time for repeat offenders.

Pro-life campaigners say the proposed new laws are an attack on their freedom of speech.