Uncertainty over the General Election meant the number of properties being listed for sale dropped to a six-year low last month, stoking price rises.

The Royal Institution of Chartered Surveyors (RICS) said prices rose in every region of the UK for the first time since August last year because of the shortage in supply.

It described the need for a pick-up in construction of new properties as a “national emergency.”

The survey found activity was sluggish across the property sector but suggested more owners would likely enter the market now the election was over.

New instructions slipped for the eighth month in a row in April, RICS said, and 72% of members questioned expected prices to rise over the course of the next 12 months.

Its expectations of price rises match the findings of other recent surveys by Nationwide and Halifax.

The Nationwide survey suggested prices had hit a new record high.

Simon Rubinsohn, chief economist at RICS, said: “It is conceivable that the decisive outcome to the election could encourage a pick-up in instructions to agents and ease some of the recent upward pressure on house prices, but it is doubtful that this will be substantive enough to provide anything more than temporary relief.”

He added new measures to increase new homes in the UK was “absolutely critical” and called on the Government to focus on measures to boost the flow of new-build properties.

“The affordability and availability of homes in the UK is now a national emergency and addressing this crisis must be the priority for the new Government.

“The last time we were building 300,000 homes was in 1963 under Harold Macmillan’s Conservative government, which utilised both public and private building.”