MPs are to vote on an amendment to the Finance Bill on Tuesday 28th June.
Announcing its support, Graeme Hughes, Group Director, said:
"Nationwide is encouraging greater scrutiny into the high-cost lending practices of legal loan sharks to ensure transparency and the protection of consumers.
"These vulnerable consumers remain at risk from a lack of transparency and the irresponsible lending practices of legal loan sharks.
"Nationwide, as a responsible lender, recently provided £3 million to Citizens Advice to fund MoneyActive financial capability volunteers in local communities."