This is the biggest slump recorded by the NAEA in over six months - October 2011 was the last time agents reported such a decrease, when FTBs made up just 16% of the market share. Prior to that, the figure has not been so low for over three years at the height of the financial crisis in December 2008, when FTBs stood at 10% of the market.
The number of house hunters registering at branches across the country also decreased, with 274 per branch in May compared with 294 in April.
Sales remained stable across the property market for a third consecutive month in May, with an average of 7 per branch. However, supply levels were bolstered during the month with an average 66 houses available, up from 62 in April.
NAEA President, Mark Hayward, said:
"Sadly, as the NAEA predicted, the Government's removal of the crucial Stamp Duty Holiday for properties priced at £250,000 and under has hit the fragile first-time buyer market hard.
"At what is a very turbulent time for the economy, both here and in the Eurozone, the major banks have introduced tighter mortgage restrictions and placed increased pressure on household finances, the Government should be doing all it can to stimulate housing market activity.
"It remains to be seen what effect the £140bn emergency funding plan, announced jointly by the Treasury and Bank of England last month will have in encouraging banks to pass on cheaper mortgages to househunters."
