Kresal said at a round table dedicated to gay marriage on Wednesday that rights for gay couples should be included in changes to the family law act instead of amendments to the act on civil unions, which envisages same-sex partnerships.
The interior minister announced that she had already raised the issue with the Minister of Labour, Family and Social Affairs Ivan Svetlik, who she said had told her that he was thinking in the same direction.
However, Svetlik is said to have expressed concern that the inclusion of gay unions into the changes being drafted to the family law act could slow down the process of finalising the law too much because this was a controversial issue.
Kresal therefore called on non-governmental organisations to pressure the government to push ahead with the changes. "You should send initiatives to the prime minster, to the leaders of parliamentary parties, to those who sit in the government," she told the debate.
Her words have sparked criticism from conservative circles, who say that now is not the time to be opening controversial issues such as gay marriage.
Ales Primc, a member of the opposition People's Party (SLS) who had campaigned in 2001 to have a referendum ban single women from accessing in-vitro fertilisation, said that Kresal was "speaking nonsense".
Primc stressed that the only basis for a family is the union between a man and woman and threatened a referendum on the matter should the government "try to equate same-sex unions and the family".
This was echoed by the non-parliamentary New Slovenia (NSi), whose minister drafted the 2005 act on civil unions, which the party believes is a suitable framework for dealing with same-sex couples.
NSi leader Ljudmila Novak added that the issue of same-sex unions should not be raised in a time of crisis, when there are more pressing issues that need to be dealt with.
While saying that the NSi respects people with same-sex orientations, Novak added that her party opposed equating "marriage in the current form with same-sex unions".
The NSi fears that giving equal treatment to same-sex couples would allow them to adopt children. Both Novak and Primc believe that children being raised by same-sex parents would be held back in their development.
Novak, a member of the European Parliament in the current term, warned that children of same-sex couples would face discrimination and stigmas.
Moreover, she said that such children would be left additionally exposed by the fact that same-sex unions "often have no lasting value" and "are more prone to diseases of modern times".
Same-sex partnerships are envisaged under the 2005 act on civil unions. The act was crafted by the previous centre-right government and has faced criticism from gay and lesbian NGOs since its adoption.
Under the act, gay and lesbian partners are able to register their union in the presence of an official. The legislation does not introduce gay marriage, but sets down rights and obligations of same-sex partners in relation to their common property and earnings, housing and inheritance.
Gay and lesbian NGOs have complained that the law fails to give partners any rights resulting from their union.
They say that the biggest shortcoming of the law is that it does not give the partners in a same-sex union the right to access health, pension or social insurance via the partner.
It also fails to give same-sex partners the status of relatives, which causes various problems. They say that this has led to only a few gay couples opting to register their partnership, even though a large majority want to do so.