May has made tackling the long-term housing shortage one of her top priorities as she looks to show voters that her government is capable of delivering domestic reforms at the same time as negotiating the country's exit from the European Union.

It is also a chance for May, weakened after losing her party's majority at last year's election and under pressure from warring factions over Brexit, to get back to her original promise to build a country "that works for everyone".

But successive British governments have failed to meet homebuilding targets, contributing to a steep rise in prices that has left many young Britons unable to afford a property and which has driven up rental prices.

May took aim at property developers, saying their bonus structures prioritise profit over the construction of affordable homes, and warned that failure to build on approved sites could affect future decisions to award new planning permission.

"I expect developers to do their duty to Britain and build the homes our country needs," May told an audience of industry leaders in London. "I want to see planning permissions going to people who are actually going to build houses, not just sit on land and watch its value rise."

The British Chambers of Commerce, which represents thousands of businesses, said firms would welcome the measures to increase house building, but added: "Planning revolutions have often been promised, but usually turn out to be a false dawn."

Britain's largest homebuilders, including Barratt, Persimmon, and Taylor-Wimpey (>> Taylor Wimpey), have reported bright starts to 2018 in recent weeks.

But May's Conservatives want 300,000 homes to be built per year -- well above the 2017 level of around 217,000.

The planning reform will also look at ways local authorities can fast-track developments without eating into protected green spaces, and give nurses, teachers, and other key workers priority access to affordable housing.

The plans will be subject to an eight week consultation, with the final version due to be published in the summer.

"The picture we see today is the result of many failures by many people over many years," May said. "Fixing it won’t happen overnight. But the size of the challenge is matched only by the strength of my ambition to tackle it."

(Reporting by William James and Elizabeth Piper; Editing by Catherine Evans)

Stocks treated in this article : Persimmon, Taylor Wimpey, Barratt Developments, Bovis Homes Group