(New York Times) — A bipartisan group of senators introduced a bill on Tuesday that would delay a new federal regulation to lower the swipe fees that banks could charge merchants for processing debit card transactions. Although there is growing uneasiness with the regulation, it is not at all clear the senators will succeed in upending the law, which easily passed the Senate last year and was a cause championed by a leading Democrat. The latest bill, introduced Tuesday by nine senators led by Senator Jon Tester, a Democrat from Montana, calls for a two-year delay and a one-year study during that period of the effect of the proposed limits on debit fees. The Dodd-Frank financial regulation bill, which became law last summer, directed the Federal Reserve Bank todetermine the limits in April and put them into effect in July. The proposed rules have faced complaints and heavy lobbying from banks, credit unions and credit card companies, which say that cutting and capping fees mean that the fees will fail to cover the cost of processing the transactions and accounting for fraud.