Britain's banks are set to swap between 80 billion and 90 billion pounds ($175 billion) of mortgage-backed assets for Treasury bills, nearly twice the base level set by the Bank of England last month, the Financial Times reported on Friday.
The British Bankers' Association said details of which banks were accessing the facility were confidential, but a spokesman said "it wouldn't be surprising" if banks were accessing more funds as there were still strains in the market.
"All of the banks are planning to use this facility," an industry source said.
"The reports in the market at the time were that it would be 50 billion to 100 billion, so this doesn't feel unexpected."
Citing debt market sources, the FT said banks had approached rating agencies about how to structure deals that will receive the necessary triple-A rating.
With banks still reluctant to lend to each other many months into the credit crunch, the Bank of England last month unveiled a plan to swap lenders' risky mortgage assets for at least 50 billion pounds of government debt.
The Bank said at the time that there was no upper limit and that the total value of the rescue plan would depend on banks' operational needs.
Governor Mervyn King said it could well "go higher" than 50 billion pounds as the figure had been based on discussions with top banks, but 119 institutions were eligible.
Friday's news, however, is likely to be read as yet another sign that lending in the interbank remains tight.
The interbank cost of borrowing three-month funds in sterling rose on Thursday to its highest level since the end of April, with spreads over secured lending rates widening as signs of rising inflation dimmed hopes of more interest rate cuts.