Over two-thirds of house builders believe that it would be impossible to build any more than 180,000 homes a year – short of the 200,000 that Labour, the Liberal Democrats and UKIP have all pledged to deliver.

A survey of over 160 developers by Knight Frank has shown that 67% believe the maximum number of new homes deliverable each year is 180,000 or fewer. Only 9% believe that over 200,000 is achievable.

The Tories have not come up with a house building target.

Knight Frank also asked the builders what measures should be taken to increase house building in the long term.

Surprisingly perhaps, given all the publicity, there was comparatively little support for Help to Buy and garden cities.

Most builders want more resources at local planning level (82%), followed by improving skills and training in the industry (58%) and access to publicly owned land (57%).

These priorities were followed by losing rules around building on the Green Belt (47%), scrapping or reviewing community infrastructure levy (44%), amending environmental requirements (39%), improving access to funding (37%), expanding Help to Buy (37%) and garden cities (26%).

Grainne Gilmore, Knight Frank head of UK residential research, said: “In the run-up to the election, all political parties agree that the delivery of more new homes is a priority.

“Yet more than two-thirds of house builders believe that under current market conditions, the maximum number of units that can be sustainably delivered each and every year is 180,000 or less.

“Policymakers, especially those in power after the election, may want to heed the calls from house builders to beef up planning departments in local authorities, plough more investment into skills and training in the construction sector and provide better access to public sector land, moves which the house building industry is signalling could move the country closer to building enough homes for all.”