The number of properties available to rent increased to 203 per member branch in March, from 197 in February, according to the latest figures released by ARLA Propertymark.
Year-on-year, supply is up 13 per cent, from the 179 available per branch in March 2018.
Demand from prospective tenants also increased, with the number of house hunters registered per branch rising to 67 on average, compared to 65 in February.
The number of tenants experiencing rent rises fell marginally in March, with 30 per cent of agents witnessing landlords increasing them, compared to 34 per cent in February.
Year-on-year, this figure is up from 23 per cent in March 2018
In March, the number of landlords exiting the market remained at four per branch. This is up from three last year.
New legislation will deter landlords from entering the market
David Cox, chief executive of ARLA Propertymark, said that while it is really positive that the number of properties available per branch hit a record high last month, this may be the first signs of the industry consolidating ahead of the tenant fees ban as agents either sell-up or merge.
He added: “This, coupled with landlords exiting the market and rent costs continuing to rise, means the overall picture is far from positive for renters.
“The full effects of the tenant fees ban have not yet been felt, and now the government is introducing yet more new legislation which will deter new landlords from entering the market, such as abolishing Section 21.
“Until we have greater clarity on the changes planned, this news will only increase pressure on the sector and discourage new landlords from investing, meaning rents will only continue to rise for tenants.”