Democratic Labour Party MP Rachel Carling-Jenkins recently introduced a private members' bill to effectively ban abortions after 24 weeks.

But on Wednesday that bill was defeated 27 votes to 11 in Parliament's 40-member Legislative Council.

However, Ms Carling-Jenkins told parliament she would not let the matter rest.

"This debate is not settled," she said. "It is not settled while the DLP holds a seat in this chamber."

The vote's failure comes after the Australian Medical Association's Victorian division urged MPs to oppose the bill.

The association released a statement that said Ms Carling-Jenkins' bill would compel doctors to perform particular types of neonatal and perinatal medical care.

AMA Victoria president Lorraine Baker said neonatal and perinatal care in Victoria was determined by doctors and their patients.

"It is world class, safe, legal and clinically appropriate," she said.

Dr Baker said the bill jeopardised good medical practice and it suggested neonatal care at a range of hospitals was inappropriate.

"This is insulting and wrong."

Abortion was decriminalised in 2008 in Victoria after a lengthy debate in parliament.

Both Labor and the Coalition had allowed a conscience vote on Wednesday.

Ms Carling-Jenkins thanked two Coalition MPs who voted with her but appeared to lash out at their colleagues who "promised to vote for this bill and now in the chamber have stated a different point of view."

Ms Carling-Jenkins also said some MPs had "fallen back" on the defence that she is a "religious ideologue".

She said she made no apologies for her Christian faith.

"I have as much right to be here and to express my opinion and the opinion of my base, that is the people who vote for me, as anyone else here does," she said.

"To continue using my religion in a derogatory light does not work for me."

Ms Carling-Jenkins said politics needed more Christian, Catholic, faith and "spirit-filled people".

Ms Carling-Jenkins also appeared to accuse some MPs of neglecting to read the bill and its accompanying explanatory memorandum.