Wells Fargospends more on lobbying from its Washington office than any rival, paying millions of dollars to influence mortgage rules, just as the San Francisco-based lender extends its lead in the market for home loans.

Last year Wells spent $7.8m on in-house lobbyists compared with $7.4m at JPMorgan, a larger bank by assets, according to congressional filings. Citigroup, Bank of America, Goldman Sachsand Morgan Stanley trail in spending even though most of them have more diverse interests or bigger reputational challenges.

If spending on lobbyists at outside companies is taken into account, JPMorgan retains a narrow lead but Wells is notable for the surge in its lobbying spending. The bank said its acquisition of Wachovia in 2008 was an explanation and it was “conservative” in disclosing the amount it spent seeking to influence the government.