Based on this post which states in part:
Ramoh in Yoreh Deah, 246:21 “A person should hire himself out for alien work rather than requiring assistance from others”; “The man who is self-sufficient is greater than the one who fears Heaven”; etc.
...Here Ramoh drives home this point even further, noting that someone who decides to busy themselves with Torah and live off charity rather than working has desecrated God's Name and brought the Torah into disrepute. He adds that Torah which is not accompanied by work leads to sin and theft (presumably because the Torah scholar/student is incapable of making a living via honest means). Similarly, the Rosh, discussing someone whose Torah is his profession, such that he is exempt from paying various taxes, defines this person as someone who only takes time away from his studies in order to earn a livelihood, “which is his obligation, for the study of Torah with derech eretz is beautiful, and if the Torah is not accompanied by work, it will end in neglect and will cause sin." This reflects the normative position amongst the Rishonim in Ashkenaz, where financing Torah study was unheard of; virtually all Torah scholars were self-supporting, and even financing Torah teaching was only reluctantly permitted by some.
...after stating the primary view, that it is forbidden and wrong for Torah scholars to receive funding, then noting a "yesh omrim," an alternate lenient view that it is permissible for rabbis to receive funding, we finally have a further lenient view that even students may receive funding. However, Ramoh notes that it is still preferable for Torah students to be self-supportive, if possible:
it would seem that it is problematic for a student to be supported full time in kollel without making any sort of income himself, especially in today's age when there are thousands of people already learning in kollel.
What then is the halachic basis for someone today to choose to learn in kollel full time without working and rely solely on someone else's support?