US lawmakers were set to propose a new law on Wednesday that would discourage people from raiding their retirement savings early to see them through tough financial times or to splash out on expensive items.

The robustness of the US retirement system has come under close scrutiny since the financial crisis crushed the value of many so-called “defined contribution” pension plans such as 401(k)s, which invested in the markets. Legislators have already proposed bills trying to improve transparency, particularly over fees and conflicts of interest.