Mortgage sales for the UK rose by £3.4bn in May, up 25.4 per cent on the previous month, according to Equifax Touchstone.
Buy-to-let figures jumped 26.1 per cent to £2.7bn, with residential up 25.2 per cent to £14.3bn.
Overall, mortgage sales for the month grew to £17bn.
Equifax Touchstone data shows that the average value of a residential mortgage in May was £200,338, compared to £194,005 in the same month of 2016.
The average buy-to-let mortgage size was £155,473, down from £160,729 in May 2016.
Every region across the UK witnessed growth in sales.
Equifax Touchstone director John Driscoll says: “Following weak figures last month, prompted by government intervention to cool buy-to-let property sales and election uncertainty, mortgage sales have rebounded in quite spectacular fashion, hitting a monthly high for 2017 of £17bn, with every single region experiencing notable growth.
“The outlook for the market however remains murky as issues such as political uncertainty linger; but we could see this sales boost continue into the summer months.”