A collective of groups lobbying for the repeal of the Eighth Amendment aims to raise and spend €500,000 during its campaign, amid growing concern over money being raised on the issue.
Health Minister Simon Harris urged both sides of the debate to adhere to electoral law and comply with the Standards in Public Office Commission (Sipo) when fundraising.
It comes after leading pro-repeal campaign groups previously failed to disclose how much they will spend campaigning for a yes vote.
The Together for Yes group said its fundraising activity was beginning from scratch but it estimates a net spend of €500,000 on its campaign.
The group was launched yesterday and is headed up by three co-directors; the director of the National Women's Council of Ireland (NWCI) Orla O'Connor, Ailbhe Smyth from the Coalition to Repeal the Eighth Amendment, and Grainne Griffin, a founding member of the Abortion Rights Campaign.
The NWCI previously said it intends to spend €70,000 campaigning, but the other two groups declined earlier opportunities to reveal financial details. Ms Smyth said most of the money raised by Together for Yes will be gathered through small donations and a significant number of donations from Irish citizens abroad.
"We are obviously just forming Together for Yes now, so we are starting from scratch effectively with donations and fundraising going on as we speak," she said.
"We intend and hope to raise something in the region of €500,000. Obviously at this stage it is very difficult to give you a precise figure for that but our working budgets are centred around that amount."
The Rape Crisis Network Ireland, Women's Aid, the Irish Family Planning Association, the Union of Students in Ireland, the Well Woman Centre and One Family are among the other groups involved in the campaign.
The Health Minister yesterday warned that is was important there was clarity about the funding and revenue streams on both sides of the debate.
Sipo regulates where large campaign groups can source income and sets out their registration obligations. Donations by foreign individuals and organisations are banned, but sums from Irish people living abroad are permitted.
"I think it is very important that regardless of your position, whether you are for or against the Eighth Amendment or campaigning for a Yes or a No, that you adhere to all of the electoral law in Ireland, and I expect everybody to do that," said Mr Harris.
Meanwhile, a group of health-care workers calling itself The Medical Alliance for the Eighth said there is "widespread opposition and concern within our profession over what the Government is proposing".
A spokesperson would not say how many healthcare workers are members of the newly-launched organisation, or who is funding it.
But she insisted the group's anti-abortion stance will be shared by the bulk of healthcare professionals.
"Abortion is life ending. It is never life-saving," she said.