A draft legislation in this regard was circulated among the Senators on Thursday by the Democratic Senator Max Baucus, who is Chairman of the powerful Senate Finance Committee. The bill also seeks to detect, deter and discourage offshore tax evasion by US companies.

In a statement, Baucus said the bill discourages businesses from moving offshore by closing a loophole in the existing legislation that results in employers in offshore tax havens avoiding payment of Social Security taxes on workers.

The draft bill proposes to modify a 2008 Heroes Act provision requiring treating as American employers any offshore entity that hires workers to perform services pursuant to a government contract.

Baucus's proposal defines an employee as anyone providing at least 100 hours of service a month, to prevent offshore employers from sidestepping the rule by calling workers "independent contractors" instead of "employees".