This figure is identical to April’s gross lending total and is 12% higher than May last year (£14.8bn).
Bob Pannell, CML chief economist, said: "Market indicators point to a slowdown in activity levels, in part associated with new mortgage rules, but it is unclear how lasting this will be.
"Implementation of the new regulatory regime is likely to have disrupted the normal patterns of activity, creating statistical "fog" around the published figures.
“As this lifts over the coming months, a clearer picture as to any lasting impact of the MMR rules on lending activity should emerge."
Henry Woodcock, principle mortgage consultant at IRESS, said the figures show that mortgage market in "cooling off" period.
He said: “After a red hot start to the year, the mortgage market has undergone a cooling off period following the implementation of the MMR.
“The combination of more stringent affordability checking, a far longer application process, not to mention more complex administration for lenders and brokers alike is pulling the rug from under the resurgent mortgage market.
“As we head into the typically slower summer months, and buyers and lenders adjust to the new regulatory environment, we are not going to see lending hit the levels seen earlier in the year.”
But whilst Woodcock thinks things will slow down he was keen to stress that the market would not come to a standstill.
He said: “There is still strong pent up demand, and many prospective borrowers are looking to move before the Bank of England acts to hike rates from historic lows.
“On top of this, buy-to-let lending continues to grow, and it will act as an increasingly important driver for overall lending.”
Whilst demand remains strong the prospect of an increase in interest rates could also deter people from buying and potentially dampen the market.
Mark Harris, chief executive of mortgage broker SPF Private Clients, said: “The threat of an interest rate rise is bound to be having an impact on people's inclination to take on new debt.
“Mark Carney's Mansion House speech sent Swap rates soaring as the markets factor in a rate rise earlier than expected and before the end of this year.
“However, inflation has fallen again suggesting that the urgency for a rate rise has once again diminished.
“While it still looks as though the first rate rise won't come before the middle of next year at the earliest, fixed-rate mortgages are becoming more expensive, and will continue to do so.
“However, borrowers shouldn't panic as 5-year fixes are still available for a little over 3% - historically, an excellent rate.
“Borrowers might want to secure a fix now though if they need certainty rather than waiting several months to see what happens.
“Ultimately, there is only one way for interest rates to move and that's upwards - it's a question of when this will happen.”
