New instructions and buyer registrations increased on a monthly basis in June across haart branches, prompting the agent to suggest that Brexit and the General Election have had little impact on the market.
Paul Smith, chief executive of haart, said even London saw stock increase by 14% during June.
However, figures painted a less rosy picture annually.
New buyer registrations were down by a fifth year-on-year, while new properties for sale fell 13.2%.
Exchanges were down 11.7% annually but just 1% down between May and June, although London branches saw the number of sales increase 3.7% on a monthly basis.
Looking at the landlord market in London, the number of sales was down 10.5% on a monthly basis but up 6.7% annually, while the number of registrations fell 13.7% between May and June and plummeted 52.7% over the year.
According to haart, June house prices averaged at £233,954, up 2.5% since May but down 0.6% on a year ago.
Smith said: “Our June data exemplifies a property market that is experiencing a boost in the wake of the General Election as house prices rise across England and Wales, in London and for first-time buyers.
“This is a far cry from predictions which are hinting around a potential housing crash, fostering home owner negativity, and do nothing for a market which relies so heavily on consumer confidence.
“Unaffordability still remains too big a barrier for many, and this will not be resolved until we improve housing supply on a bigger scale than ever seen before.
“This can only be achieved when we resolve the gridlock that is house-building, and introduce incentives for greater fluidity in the market.”