Nationwide's first quarter pre-tax profit dipped by a fifth as the country's biggest building society said that the finance industry was facing a tough time ahead because of fears of an economic slowdown and tighter lending rules that could squeeze the housing market.
The UK's biggest mortgage lender said that pre-tax profit was £322 million in the three months to the end of June, down from £401 million in the same period a year ago.
The lender stressed the two periods were "broadly consistent", after allowing for a £26m one-off gain this quarter and a one-off £100m gain for the same time past year.
This was partly because Nationwide changed its underwriting criteria for buy-to-let mortgages.
The largest mutual reported profits falls before tax of £322m, down from £401m in Q1 2017 and underlying profit before tax of £301m, also down from £368m in the same period a year ago.
"This, together with a softening of lending due to Stamp Duty and tax changes, led to a decline in buy-to-let".
Its Q1 results showed gross buy-to-let volumes at just under half last years' results at £0.8bn compared to £1.7bn in Q1 2016.
Chief executive Joe Garner said that while consumers were becoming more anxious about the United Kingdom outlook - which has turned gloomier as Brexit approaches - most did not see the fall-out from the European Union referendum affecting their access to borrowing.
The building society saw 202,000 new current accounts opened, up from 173,000 in the same period a year ago.
Gross mortgage lending at the building society was £8.1bn for the quarter, down slightly on the £8.6bn it reported for the same period a year ago.
The lender said on Friday that although the British public had become less optimistic about the economic outlook, research conducted for its Brexit Consumer Support Panel showed the majority of consumers expect Britain's European Union exit to leave their ability to access credit unchanged.
"In a period of potentially prolonged economic uncertainty and persistently low interest rates Nationwide continues to invest in products and services to support the long-term needs of our members".