HomeLet is warning that the “steady rental growth” being enjoyed by landlords could soon change as Brexit gets under way.

Figures from the tenancy referencing provider show average UK rents were up 1.7% annually in September at £943 a month.

When London is excluded the average rent is up 1.8% to £780.

Despite annual increases in all regions except the north-east, rents did fall on a monthly basis by 0.4% across the UK.

HomeLet said these figures are in line with previous rental inflation figures, but warned that the environment could be set to get tougher for tenants.

It has provided some early findings from its annual landlord survey – set to be released in November – showing that 36% of landlords cited Brexit as their biggest concern, alongside the possibility of increased regulation through legislation and changes to house prices.

Martin Totty, chief executive at HomeLet, said: “While more than 90% of landlords intend to either keep or expand their property portfolio in the next 12 months, they are not without their concerns.

“Our initial results show that the three main concerns that landlords have are the macro-economic impacts they face on their finances – further changes to legislation, the potential implications of Brexit and house price values.

“The results suggest that while landlords are not planning to leave the market at this stage, uncertainty over the wider economic picture – especially when Brexit is added into the mix – could easily change this.

“The current steady growth within the private rental sector suits the needs of both tenants and landlords.

“However, should landlords change their stance and begin to exit the market, therefore reducing the supply of rental properties, there is a possibility that rental prices could rise, as at this stage there is no indication that the demand for rental properties is going down.”