Gross lending by building societies increased 44% year-on-year in July, the BSA said.

Mutuals lent £3.1bn in July compared to £2.1bn in the same month the year before. Lending also increased 14% on June’s figures, which stood at £2.7bn.

The number of mortgages approved by mutuals was up 47% in July, at 2,786, compared to the same month last year at 1,891.

Adrian Coles, director-general of the Building Societies Association, said: “Mutuals are currently enjoying a sustained increase in lending activity, and an increase in deposits from savers.

“Lending activity by mutuals has been growing strongly on a year-on-year basis for some time now, and in July gross lending rose again by a healthy 44%. At the same time lending by banks fell by 9% in July.

“As a result mutuals continue to take market share, up to 24% in July, well above the 17% figure for the same month on 2011. Approvals by mutuals were also up in the month and this means that this trend of increased lending is likely to continue.”