Fianna Fáil is poised to block moves by a number of banks to sell off tens of thousands of mortgages, according to the Sunday Business Post.
The opposition party is set to invoke its confidence and supply agreement to prevent the sale of distressed mortgages to unregulated vulture funds.
The party is set to publish a bill which could put a halt to the likes of Permanent TSB's plans to sell 20,000 struggling mortgages.
Ulster Bank is also preparing to offload non-performing loans, and it is expected they will signal their plans to sell off more loan portfolios.
The Sunday Business Post report that AIB will look to sell off their distressed commercial and investment property debt by the end of this year, or early 2019.